Conceptual Physics Daily 10

Conceptual Physics Daily 10
Adapted from physicsclassroom.com

Which of these is a scientific
hypothesis? a. Atoms are the smallest particle of matter that exists. b. Albert Einstein is the greatest scientist of the twentieth century. c. The universe is surrounded by a second universe that cannot be seen. SCSh7, SCSh7e,SCSh8,SCSh8a

2. To test a scientific hypothesis you would:
Use the results of only the experiment that confirm the hypothesis. b. Set up an experiment and look at the results. c. Find the best result and report only that result. d. Set up many experiments and look at the results. SCSh7, SCSh7e,SCSh8,SCSh8a

3. A scientific hypothesis may turn out to be right or it may turn out to be wrong.
If it is a valid hypothesis, there must be a test to prove it a. right b. wrong SCSh7, SCSh7e,SCSh8,SCSh8a

3. A scientific hypothesis may turn out to be right or it may turn out to be wrong.
If it is a valid hypothesis, there must be a test to prove it right wrong SCSh7, SCSh7e,SCSh8,SCSh8a

4. The difference between a hypothesis and a theory is that a hypothesis is
never true whereas a theory is always true true whereas a theory is not true never true whereas a theory is sometimes true an educated guess whereas a theory has been tested successfully many times SCSh7, SCSh7e,SCSh8,SCSh8a

4. The difference between a hypothesis and a theory is that a hypothesis is
never true whereas a theory is always true true whereas a theory is not true never true whereas a theory is sometimes true d. an educated guess whereas a theory has been tested successfully many times SCSh7, SCSh7e,SCSh8,SCSh8a

5. A scalar quantity has only direction only magnitude both magnitude and direction neither magnitude or direction SP1b,SP1b,SP1f

5. A scalar quantity has only direction b. only magnitude both magnitude and direction neither magnitude or direction SP1b,SP1b,SP1f

6. What is needed to describe a vector quantity?
only magnitude only direction both magnitude and direction Neither magnitude nor direction SP1b,SP1b,SP1f

7. Equilibrium occurs when
all the forces acting on an object are balanced. the sum of the + forces equals the sum of the – forces. the net force on the object is zero. the sum of the upward forces equals the sum of the downward forces. all of the above. SP1b,SP1b,SP1f

8. What is the maximum resultant possible when adding a 3N force and a 5N force?
SP1b,SP1b,SP1f

9. What is the minimum resultant possible when adding a 3N force and a 5N force?
SP1b,SP1b,SP1f

10. A barge is being pulled along a canal by two ropes that make equal angles with the direction in which the barge points. Assuming the two pulls on the barge are equal, in what direction does the barge move? It oscillates back and forth between the two banks. It moves straight forward. It moves in the direction of the resultant force on it. Both a and b Both b and c SP1b,SP1b,SP1f

11. The astronomer Copernicus publicly stated in the 1500s that Earth
a. does not move b. revolves around the sun. c. is slowing down. d. moves in a straight line. e. is the center of the solar system. SP1d

12.The law of inertia applies to
a. objects at rest. b. moving objects. c. both moving and nonmoving objects. SP1d

13. Friction a. comes from microscopic bumps that act as obstructions to the object's motion. b. is the name given to the force acting between surfaces sliding past one another. c. acts in a direction that opposes the motion of an object. d. all of the above e. none of the above

13. Friction a. comes from microscopic bumps that act as obstructions to the object's motion. b. is the name given to the force acting between surfaces sliding past one another. c. acts in a direction that opposes the motion of an object. d. all of the above e. none of the above SP1d

14. Which has more mass, a kilogram of feathers or a kilogram of iron?
The feathers The iron c. Neither—they both have the same mass. SP1d

15. How much does a 3.0-kg bag of bolts weigh?
a.7.2 N b.14.4 N c.22.8 N d.29.4 N e.58.8 N SP1d

16. On the surface of the Moon, a ball is thrown straight up with an initial velocity. The ball has a constant acceleration due to the Moon’s gravity. On a graph of the ball’s velocity versus time, which of the following would represent the ball at its highest point above the Moon’s surface? A. when the velocity is equal to 0 m/s B. when the velocity is equal to 1.6 m/s C. when the velocity has its greatest value D. when the velocity has its most negative value SPS8 a

17. A rocket is launched at a speed of 10 kilometers per second
17. A rocket is launched at a speed of 10 kilometers per second. How far will it travel in 1/2 minute? A. 300 km B. 5 km C m D. 600 m SPS8 a

18. Speed is a measure of how fast something is moving. always measured in terms of a unit of distance divided by a unit of time. the distance covered per unit time. all of the above. none of the above. SP1a,b

19. One possible unit of speed is
miles per hour. light years per century. kilometers per hour. all of the above none of the above. SP1a,b

20. An elevator in an office building completed the following trips: • 1st floor to 8th floor • 8th floor to 4th floor • 4th floor to 13th floor The distance between each floor of the office building is 3.0 m. Which table shows the total distance traveled and displacement of the elevator? SP1a,b

SP1a,b

21. The table below shows the time it takes four cars to go from 0 to 60 km/h. Based on the information given, which of the following quantities can be compared for the four cars? A. average acceleration B. instantaneous speed C. stopping distance D. stopping time SP1a,b

22. If an object has an acceleration
of 0 m/s2, then one can be sure that the object is not ____. moving changing position changing velocity SP1a,b

23. Which one of the following
statements is NOT true of a free-falling object? An object in a state of free fall ____. a. falls with a constant speed of -10 m/s. b. falls with a acceleration of -10 m/s/s. c. falls under the sole influence of gravity. d. falls with downward acceleration which has a constant magnitude. SP1a,b

23. Which one of the following statements is NOT true of a
free-falling object? An object in a state of free fall ____. a. falls with a constant speed of -10 m/s. b. falls with a acceleration of -10 m/s/s. c. falls under the sole influence of gravity. d. falls with downward acceleration which has a constant magnitude. SP1a,b

24. Which of the following statements about free fall and the acceleration of gravity are TRUE? List all that apply. a. An object that is free-falling is acted upon by the force of gravity alone. b. A falling skydiver which has reached terminal velocity is considered to be in a state of free fall. c. A ball is thrown upwards and is rising towards its peak. As it rises upwards, it is NOT considered to be in a state of free fall SP1a,b

d. An object in free fall experiences an
acceleration which is independent of the mass of the object. e. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. As the ball rises, its acceleration is upwards; as it falls, its acceleration is downwards. SP1a,b

f. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. The speed at which it is launched equals the speed at which it lands. (Assume negligible air resistance.) g. A very massive object will free fall at the same rate of acceleration as a less massive object. SP1a,b

h. The value of g on Earth is approximately 9.8 m/s2.
The symbol g stands for the force of gravity. SP1a,b

a. An object that is free-falling is acted
upon by the force of gravity alone. TRUE - Yes! This is the definition of free fall.

b. A falling skydiver which has reached terminal velocity is considered to be in a state of free fall. FALSE - Skydivers which are falling at terminal velocity are acted upon by large amounts of air resistance. They are experiencing more forces than the force of gravity. As such, they are NOT free-falling.

c. A ball is thrown upwards and is rising towards its peak
c. A ball is thrown upwards and is rising towards its peak. As it rises upwards, it is NOT considered to be in a state of free fall. FALSE - Any object - whether rising, falling or moving horizontally and vertically simultaneously - can be in a state of free fall if the only force acting upon it is the force of gravity. Such objects are known as projectiles and often begin their motion while rising upwards.

d. An object in free fall experiences an acceleration which is independent of the mass of the object. TRUE - The unique feature of free-falling objects is that the mass of the object does not effect the trajectory characteristics. The acceleration, velocity, displacement, etc. is independent of the mass of the object.

e. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. As the ball rises, its acceleration is upwards; as it falls, its acceleration is downwards. FALSE - The acceleration of all free-falling objects is directed downwards. A rising object slows down due to the downward gravity force. An upward-moving object which is slowing down is said to have a downwards acceleration.

f. A ball is thrown upwards, rises to its peak and eventually falls back to the original height. The speed at which it is launched equals the speed at which it lands. (Assume negligible air resistance.) TRUE - If the object is truly in free-fall, then the speed of the object will be the same at all heights - whether its on the upward portion of its trajectory or the downwards portion of its trajectory.

g. A very massive object will free fall at the same rate of acceleration as a less massive object.
TRUE - The acceleration of free-falling objects (referred to as the acceleration of gravity) is independent of mass. On Earth, the value is 9.8 m/s/s (the direction is down). All objects - very massive and less massive - experience this acceleration value.

h.The value of g on Earth is
approximately 9.8 m/s2. TRUE - Yes! Know this one!

i.The symbol g stands for the force
of gravity. FALSE - Nope. g is known as the acceleration of gravity. It might be best to call it the acceleration caused by gravity. When it comes to the force of gravity, we have yet another symbol for that - Fgrav.

25. If car A passes car B, then car A must be ____.
a. accelerating. b. accelerating at a greater rate than car B. c. moving faster than car B and accelerating more than car B. d. moving faster than car B, but not necessarily accelerating. SP1a,b

SP1a,b 25. If car A passes car B, then car A must be ____.
a. accelerating. b. accelerating at a greater rate than car B. c. moving faster than car B and accelerating more than car B. d. moving faster than car B, but not necessarily accelerating. All that is necessary is that car A has a greater speed (is moving faster). If so, it will eventually catch up and pass car B. Acceleration is not necessary to overcome car B SP1a,b

c. remain at a relatively fixed distance from one another
26. Consider drops of water that leak from a dripping faucet at a constant rate. As the drops fall they ____. a. get closer together b. get farther apart c. remain at a relatively fixed distance from one another SP1a,b

26.Consider drops of water that leak from a dripping faucet at a constant rate. As the drops fall they ____. a. get closer together b. get farther apart c. remain at a relatively fixed distance from one another Since the drops of water are falling (and probably free-falling), they should be getting farther apart as they fall. This is because the free-falling drops are accelerating and thus gaining speed. SP1a,b

27. If an object is moving eastward and slowing down, then the direction of its velocity vector is ____. eastward westward neither not enough information to tell SP1a,b

28. If an object is moving eastward and slowing down, then the direction of its acceleration vector is ____. eastward westward neither not enough information to tell SP1a,b

28. If an object is moving eastward and slowing down, then the direction of its velocity vector is ____. eastward westward neither not enough information to tell SP1a,b

29. The average speed of an object which moves 10 kilometers (km) in 30 minutes is ____.
10km/hr 20km/hr 30km/hr more than 30km/hr SP1a,b

29. The average speed of an object which moves 10 kilometers (km) in 30 minutes is ____.
10km/hr 20km/hr 30km/hr more than 30km/hr The average speed is distance/time. In this case the distance is 10 km and the time is 0.5 hr (30 minutes). Thus average speed = (10 km)/(0.5 hr) = 20 km/hr SP1a,b

30. As an object freely falls, its ____.
a. speed increases b. acceleration increases c. both of these d. neither of these SP1a,b

30. As an object freely falls, its ____.
a. speed increases b. acceleration increases c. both of these d. neither of these As an object falls, it accelerates; this means that the speed will be changing. While falling, the speed increases by 10 m/s every second. The acceleration is a constant value of 10 m/s/s; SP1a,b

31. On takeoff, a rocket accelerates from rest at a rate of 50 m/s2 for exactly 1 minute. The rocket's speed after this minute of steady acceleration will be ____ m/s. 50 500 3x10E3 3.6x10E3 none of these SP1a,b

31. On takeoff, a rocket accelerates from rest at a rate of 50 m/s2 for exactly 1 minute. The rocket's speed after this minute of steady acceleration will be ____ m/s. 50 500 3.00x103 3.60x103 none of these Use the equation vf = vi + a*t vf = 0 + (50.0 m/s/s)*(60.0 s) = 3.00 x 103 m/s SP1a,b

32. When a rock is dropped, it will accelerate downward at a rate of 9
32. When a rock is dropped, it will accelerate downward at a rate of 9.8 m/s2. If the same rock is thrown downward (instead of being dropped from rest), its acceleration will be ____. (Ignore air resistance effects.) less than 9.8m/s2 9.8m/s2 more than 9.8m/s2 SP1a,b

32. When a rock is dropped, it will accelerate downward at a rate of 9
32. When a rock is dropped, it will accelerate downward at a rate of 9.8 m/s2. If the same rock is thrown downward (instead of being dropped from rest), its acceleration will be ____. (Ignore air resistance effects.) less than 9.8m/s2 9.8m/s2 more than 9.8m/s2 Whether rising or falling, if the sole force acting upon the object is gravity, then the acceleration is 9.8 m/s/s (often approximated as 10 m/s/s). SP1a,b

33. Ima Rilla Saari is cruising at 28
33. Ima Rilla Saari is cruising at 28.0 m/s down Lake Avenue and through the forest preserve. She notices a deer jump into the road at a location 62.0 m in front of her. Ima first reacts to the event, then slams on her brakes and decelerates at m/s2, and ultimately stops a picometer in front of the frozen deer. What is Ima's reaction time? (i.e., how long did it take Ima to react to the event prior to decelerating? SP1a,b

33. Ima's total distance traveled (62
33. Ima's total distance traveled (62.0 m) can be broken into two segments - a reaction distance (drxn) and a braking distance (dbraking). The reaction distance is the distance Ima moves prior to braking; she will move at constant speed during this time of trxn. SP1a,b

33. The braking distance is the distance which Ima moves when her foot is on the brake and she decelerates from 28.0 m/s to 0.0 m/s. The braking distance can be computed first using the following kinematic equation: vf2 = vo2 + 2*a*d. The known information for this braking period is: vo = 28.0 m/s; vf = 0 m/s; and a = m/s/s. SP1a,b

33. vf2 = vo2 + 2*a*d. The known information for this braking period is: vo = 28.0 m/s; vf = 0 m/s; and a = m/s/s. dbraking = (vf2 - vo2) / (2*a) = [(0 m/s)2 - (280 m/s)2 ] / (2 * m/s/s) = m SP1a,b

33. Since Ima's car requires 48
33. Since Ima's car requires m to brake, she can travel a maximum of 13.6 m during the reaction period. The relationship between reaction time, speed and reaction distance is given by the equation drxn = v * trxn SP1a,b

33. drxn = v * trxn Substituting 13.6 m for drxn and 28.0 m/s for v, the reaction time can be computed: trxn = (13.6 m) / (28.0 m/s) = s SP1a,b

34. Construct free-body diagrams for the following physical situations.
a. A ball is dropped from rest from the top of a building. Assume negligible air resistance. In the absence of Fair, the only force acting upon the ball is gravity. It is a projectile. SP1f

34b. After being thrown, a football is moving upwards and rightwards towards the peak of its trajectory. Assume negligible air resistance. In the absence of Fair, the only force acting upon the ball is gravity. It is a projectile. Note that an upwards moving object does not need an upwards force. Only an upwards accelerating object requires an upwards force. SP1f SP1a,b

34c. After reaching a terminal velocity, the falling skydiver then opens a parachute.
When the terminal velocity was reached, Fa = Fg. Then the parachute was opened, making Fair even greater than before. This is represented by the larger arrow. SP1f

34d. An air track glider is gliding to the right at constant velocity.
There is no rightwards force. A rightwards force would only be required if there is a rightwards acceleration. If the glider is gliding; there is no mention of it being pushed or pulled (Fapp) and if there is a constant velocity, there must be balanced forces. SP1f

34e. A car is skidding to a stop while traveling to the right.
There is no rightwards force. A rightwards force would only be required if there is a rightwards acceleration. If the car is skidding (wheels are locked), friction acts in a direction opposite its motion to slow it down. SP1f SP1a,b

34f. A downward moving elevator (held by a cable) slows down.
The cable supplies the tension force. Since the elevator is moving downwards and slowing down, there must be more upwards force than the downwards gravity force. SP1f SP1a,b

34g. A 25.0-N force is applied at a 30-degree angle to a crate in order to accelerate it rightward across a rough, horizontal surface. The applied force is upwards and rightwards. Its upward component contributes to the upwards Fn to balance the force of gravity. (Note the relative size of Fn.) SP1f SP1a,b

34h. A picture hangs symmetrically by two wires oriented at angles to the vertical.
The force exerted by a wire is a tension force. With two wires, there would be two upwards-pulling tension forces. The down force is gravity. SP1f

34i. A large crate slowly accelerated down a steep and rough inclined plane.
There are only three forces present. The Fpar and Fperp are merely components of gravity; they are not separate forces. The normal force is perpendicular to the surface (drawn in blue). SP1f SP1a,b

35. Which of the following are always true of an object that is at equilibrium? Include all that apply. a. All the forces acting upon the object are equal. b. The object is at rest. c. The object is moving and moving with a constant velocity. d. The object has an acceleration of zero. e. There is no change in the object's velocity. f. The sum of all the forces is 0 N. g. All the forces acting upon an object are balanced SP1f SP1a,b

36. Which one(s) of the following force diagrams depict an object moving to the right with constant speed? Write all possible answers (if any) in the blank: ________________ Explain your answer. SP1f

36. Which one(s) of the following force diagrams depict an object moving to the right with constant speed? Write all possible answers (if any) in the blank: a and c SP1f

37. How much net force is required to keep a 5-kg object moving rightward with a constant velocity of 2 m/s? ________ Explain or show your work. SP1f

37. How much net force is required to keep a 5-kg object moving rightward with a constant velocity of 2 m/s? ________ Explain or show your work. Answer: 0 N If the velocity is constant, then the acceleration is 0 m/s/s and the net force is zero. A net force is only required in order to accelerate an object. SP1f

38. Solve for the missing quantities.
Fa = ________N Fg = 700 N m = ________ a = 5.0m/s/s left SP1f

38. SP1f

both vertical and horizontal
39. A ball is thrown into the air at some angle. At the very top of its path, the velocity is: entirely vertical entirely horizontal both vertical and horizontal there is not enough information to determine. SP1f

40. A 50-N force is applied at an angle of 30 degrees north of east
40. A 50-N force is applied at an angle of 30 degrees north of east. This would be the same as applying two forces at a. 43 N, east and 7 N, north b. 35 N, east and 15 N, north c. 25 N, east and 25 N, north 43 N, east and 25 N, north SP1f SP1a,b

40. A 50-N force is applied at an angle of 30 degrees north of east
40. A 50-N force is applied at an angle of 30 degrees north of east. This would be the same as applying two forces at a. 43 N, east and 7 N, north b. 35 N, east and 15 N, north c. 25 N, east and 25 N, north 43 N, east and 25 N, north Answer: D A 50-N force at 30 degrees would have two components - 43 N, east and 25 N, north. These two forces would be equal to the 50-N force at 30 degrees N of E. They are calculated as: Feast = (50 N)*cos(30 deg) Fnorth = (50 N)*sin(30 deg) SP1f SP1a,b

41. An object rests upon an inclined plane
41. An object rests upon an inclined plane. If the angle of incline is increased, then the normal force would _______. increase decrease remain the same SP1f

41. An object rests upon an inclined plane
41. An object rests upon an inclined plane. If the angle of incline is increased, then the normal force would _______. increase decrease remain the same The normal force is equal to the perpendicular component of the weight vector. So Fnorm = Fperp = mgcos(angle). If the incline angle is increased, the cos(angle) decreases towards 0; thus, the normal force decreases as well. SP1f

Determine: (a) the horizontal displacement, and
42. A ball is projected horizontally from the top of a 92.0-meter high cliff with an initial speed of 19.8 m/s. Determine: (a) the horizontal displacement, and (b) the final speed the instant prior to hitting the ground. Use g= 9.8 m/s2 SP1f

base of a 19.3-meter high cliff.
43. Determine the launch speed of a horizontally-launched projectile which lands 26.3 meters from the base of a 19.3-meter high cliff. SP1f

the base of the field house. Determine the height of the field house.
44. A soccer ball is kicked horizontally at 15.8 m/s off the top of a field house and lands 33.9 meters from the base of the field house. Determine the height of the field house. SP1f

45. Which of the following statements are true of inertia?
a. Inertia is a force. b. Inertia is a force which keeps stationary objects at rest and moving objects in motion at constant velocity. c. Inertia is a force which brings all objects to a rest position. d. All objects have inertia. SP1f

f. Fast-moving objects have more inertia than slow-moving objects.
45. e. A more massive object has more inertia than a less massive object. f. Fast-moving objects have more inertia than slow-moving objects. g. An object would not have any inertia in a gravity-free environment (if there is such a place). h. Inertia is the tendency of all objects to resist motion and ultimately stop. SP1f

45. i. In a gravity-free environment (should there be one), a person with a lot of inertia would have the same ability to make a turn as a person with a small amount of inertia. SP1f

45. Which of the following statements are true of inertia?
a. Inertia is a force. FALSE b. Inertia is a force which keeps stationary objects at rest and moving objects in motion at constant velocity. FALSE c. Inertia is a force which brings all objects to a rest position. FALSE d. All objects have inertia. TRUE SP1f

45. e. A more massive object has more inertia than a less massive object. TRUE
f. Fast-moving objects have more inertia than slow-moving objects. FALSE g. An object would not have any inertia in a gravity-free environment (if there is such a place). FALSE h. Inertia is the tendency of all objects to resist motion and ultimately stop. FALSE

45. i. In a gravity-free environment (should there be one), a person with a lot of inertia would have the same ability to make a turn as a person with a small amount of inertia. FALSE SP1f

46. Which of the following statements are true of the quantity mass?
a. The mass of an object is dependent upon the value of the acceleration of gravity. b. The standard metric unit of mass is the kilogram. c. Mass depends on how much stuff is present in an object. SP1a,d

d. The mass of an object is variable and dependent upon its location.
e. An object would have more mass on Mount Everest than the same object in the middle of Lake Michigan. SP1a,d

g. The mass of an object can be measured in pounds.
f. People in Weight Watcher's are really concerned about their mass (they're mass watchers). g. The mass of an object can be measured in pounds. If all other variables are equal, then an object with a greater mass would have a more difficult time accelerating. SP1a,d

i. If all other variables are equal, then it would require less exerted force to stop a less massive object than to stop a more massive object. j. The mass of an object is mathematically related to the weight of the object. SP1a,d

46. Which of the following statements are true of the quantity mass?
a. The mass of an object is dependent upon the value of the acceleration of gravity. FALSE b. The standard metric unit of mass is the kilogram. TRUE c. Mass depends on how much stuff is present in an object. TRUE SP1a,d

d. The mass of an object is variable and dependent upon its location
d. The mass of an object is variable and dependent upon its location. FALSE e. An object would have more mass on Mount Everest than the same object in the middle of Lake Michigan. FALSE SP1a,d

g. The mass of an object can be measured in pounds. FALSE
f. People in Weight Watcher's are really concerned about their mass (they're mass watchers). TRUE g. The mass of an object can be measured in pounds. FALSE If all other variables are equal, then an object with a greater mass would have a more difficult time accelerating. TRUE SP1a,d

i. If all other variables are equal, then it would require less exerted force to stop a less massive object than to stop a more massive object. TRUE j. The mass of an object is mathematically related to the weight of the object. TRUE SP1a,d

b. Weight refers to a force experienced by an object.
47. Which of the following statements are true of the quantity weight? List all that apply. a. The weight of an object is dependent upon the value of the acceleration of gravity. b. Weight refers to a force experienced by an object. c. The weight of an object would be less on the Moon than on the Earth. SP1a,d

e. Two objects of the same mass can weigh differently.
47. d. A person could reduce their weight significantly by taking an airplane ride to the top of Mount Everest. e. Two objects of the same mass can weigh differently. f. To gain weight, one must put on more mass. g. The weight of an object can be measured in kilograms. SP1a,d

47. h. The weight of an object is equal to the force of gravity acting upon the object. i. When a chemistry student places a beaker on a balance and determines it to be 84.3 grams, they have weighed the beaker. SP1a,d

b. Weight refers to a force experienced by an object. TRUE
47. Which of the following statements are true of the quantity weight? List all that apply. a. The weight of an object is dependent upon the value of the acceleration of gravity. TRUE b. Weight refers to a force experienced by an object. TRUE c. The weight of an object would be less on the Moon than on the Earth. TRUE SP1a,d

g. The weight of an object can be measured in kilograms. FALSE
47. d. A person could reduce their weight significantly by taking an airplane ride to the top of Mount Everest. FALSE e. Two objects of the same mass can weigh differently. True (at different gravitational locations) f. To gain weight, one must put on more mass. Mostly TRUE (or change gravitational force) g. The weight of an object can be measured in kilograms. FALSE SP1a,d

47. h. The weight of an object is equal to the force of gravity acting upon the object. TRUE i. When a chemistry student places a beaker on a balance and determines it to be 84.3 grams, they have weighed the beaker. FALSE SP1a,d

48. The amount of net force required to keep a 5-kg object moving rightward with a constant velocity of 2 m/s is ____. 0 N 0.4 N 2.0 N 2.5 N 5.0N SP1a,d

1/6-th that of Earth's? ________ Explain or show your work.
49. A. Big Bubba has a mass of 100 kg on the earth. What is Big Bubba's mass on the moon where the force of gravity is approximately 1/6-th that of Earth's? ________ Explain or show your work. b. Little Billie weighs 360 N on Earth. What is Little Billie's mass on the moon where the force of gravity is approximately 1/6-th that of Earth's? ________ Explain or show your work. SP1a,d

1/6-th that of Earth's? ________ Explain or show your work.
49. A. Big Bubba has a mass of 100 kg on the earth. What is Big Bubba's mass on the moon where the force of gravity is approximately 1/6-th that of Earth's? ________ Explain or show your work. Answer: 100 kg Mass is a quantity which is independent of the location of the object. So if Big Bubba has a mass of 100 kg on Earth, then he also has a mass of 100 kg on the moon. Only the weight would change as Big Bubba is moved from the Earth to the moon. SP1a,d

49. b. Little Billie weighs 360 N on Earth. What is Little Billie's mass on the moon where the force of gravity is approximately 1/6-th that of Earth's? ________ Explain or show your work. Answer: ~36 kg The mass of an object is related to weight by the equation W = mg where g = ~10 m/s/s on Earth and one-sixth this value (~1.67) on the moon. So if Billy weighs 360 N on Earth, then his mass is approximately ~36 kg. His mass on the moon will be the same as his mass on Earth. SP1a,d

c. Accelerating objects are either slowing down or speeding up.
50. Consider Newton's second law of motion to determine which of the following statements are true? List all that apply. a. If an object is accelerating to the right, the net force on the object must be directed towards the right. b. If an object is moving to the right and slowing down, then the net force on the object is directed towards the left. c. Accelerating objects are either slowing down or speeding up. SP1a,d

50. d. The acceleration of an object is directly dependent upon its mass and inversely dependent upon its net force. e. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2, then the new acceleration would be 10 m/s/s. f. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 3, then the new acceleration would be 11 m/s/s. SP1a,d

An object has an acceleration of 8 m/s/s. If
50. g. An object has an acceleration of 8 m/s/s. If the mass of the object is increased by a factor of 2, then the new acceleration would be 16 m/s/s. h. An object has an acceleration of 8 m/s/s. If the mass of the object is increased by a factor of 4, then the new acceleration would be 2 m/s/s. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2 and the mass of the object is decreased by a factor of 2, the acceleration would still be 8 m/s/s. SP1a,d

50. j. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2 and the mass of the object is increased by a factor of 4, then the new acceleration would be 4 m/s/s. k. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is decreased by a factor of 2 and the mass of the object is increased by a factor of 4, then the new acceleration would be 1 m/s/s. SP1a,d

50. l. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 4 and the mass of the object is increased by a factor of 2, then the new acceleration would be 16 m/s/s. m. A 2-kg object accelerates from rest to a final velocity of 6 m/s in 3 seconds. The net force acting upon the object is 12 N. SP1a,d

50. n. A 10-kg object slows down from 24 m/s to a final velocity of 9 m/s in 3 seconds. The net force acting upon the object is 80 N. SP1a,d

c. Accelerating objects are either slowing down or speeding up. FALSE
50. Consider Newton's second law of motion to determine which of the following statements are true? List all that apply. a. If an object is accelerating to the right, the net force on the object must be directed towards the right. TRUE b. If an object is moving to the right and slowing down, then the net force on the object is directed towards the left. TRUE c. Accelerating objects are either slowing down or speeding up. FALSE SP1a,d

50. d. The acceleration of an object is directly dependent upon its mass and inversely dependent upon its net force. FALSE e. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2, then the new acceleration would be 10 m/s/s. FALSE f. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 3, then the new acceleration would be 11 m/s/s. FALSE SP1a,d

50. g. An object has an acceleration of 8 m/s/s
50. g. An object has an acceleration of 8 m/s/s. If the mass of the object is increased by a factor of 2, then the new acceleration would be 16 m/s/s. FALSE h. An object has an acceleration of 8 m/s/s. If the mass of the object is increased by a factor of 4, then the new acceleration would be 2 m/s/s. TRUE An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2 and the mass of the object is decreased by a factor of 2, the acceleration would still be 8 m/s/s. FALSE

50. j. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 2 and the mass of the object is increased by a factor of 4, then the new acceleration would be 4 m/s/s. TRUE k. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is decreased by a factor of 2 and the mass of the object is increased by a factor of 4, then the new acceleration would be 1 m/s/s. TRUE SP1a,d

50. l. An object has an acceleration of 8 m/s/s. If the net force acting upon the object is increased by a factor of 4 and the mass of the object is increased by a factor of 2, then the new acceleration would be 16 m/s/s. TRUE m. A 2-kg object accelerates from rest to a final velocity of 6 m/s in 3 seconds. The net force acting upon the object is 12 N. FALSE SP1a,d

50. n. A 10-kg object slows down from 24 m/s to a final velocity of 9 m/s in 3 seconds. The net force acting upon the object is 80 N. FALSE SP1a,d

51. TRUE or FALSE: For an object resting upon a non-accelerating surface, the normal force is equal to the weight of the object. SP1a,d

51. TRUE or FALSE: For an object resting upon a non-accelerating surface, the normal force is equal to the weight of the object. Answer: False The normal force is not necessarily always equal to the weight of an object. Suppose that a person weighs 800 N and sits at rest upon a table. Then suppose another person comes along and pushes downwards upon the persons shoulders, applying a downward force of 200 N. The normal force becomes 1000N. SP1a,d

According to Newton's third law, every force is accompanied by an equal and opposite reaction force. The reason that these forces do not cancel each other is ____. a. the action force acts for a longer time period b. the two forces are not always in the same direction c. one of the two forces is greater than the other d. the two forces act upon different objects; only forces on the same object can balance each other. e. ... nonsense! They do cancel each other. Objects accelerate because of the presence of a third force SP1a,d

52. Answer: D Action and reaction forces always act upon the interacting objects for the same amount of time with the same magnitude. So if object A pushes on object B, then object B simultaneously pushes on object A with the same amount of force. The force on object B will be one of perhaps many forces which will govern its motion. But the reaction force is on object A and cannot contribute to object B's motion since it is not acting upon object B. Action-reaction forces can NEVER cancel each other. SP1a,d

53. As you sit in your chair and study your physics (presuming that you do), the force of gravity acts downward upon your body. The reaction force to the force of the Earth pulling you downward is ___. a. the force of the chair pushing you upward b. the force of the floor pushing your chair upward c. the force of the Earth pushing you upward d. the force of air molecules pushing you upwards e. the force of your body pulling the Earth upwards f. ... nonsense! Gravity is a field force and there is no such reaction force. SP1a,d

53. Answer: E The most common wrong answer is a - the force of the chair pushing you upward. As you sit in your chair, the chair is indeed pushing you upward but this is not the reaction force to the force of the Earth pulling you downward. The chair pushing you upward is the reaction force to you sitting on it and pushing the chair downward. So if the Earth pulls you downward, then the reaction force is you pull the Earth upward. SP1a,d

54. A golf pro places a ball at rest on the tee, lines up his shot, draws back his club, and lets one rip. During the contact of the golf club with the golf ball, the force of the club on the ball is ____ the force of the ball on the club and the acceleration of the club is ____ than the acceleration of the ball. greater than, greater than b. greater than, equal to greater than, less than less than, less than less than, equal to less than, greater than equal to, equal to equal to, greater than equal to, less than SP1a,d

54. A golf pro places a ball at rest on the tee, lines up his shot, draws back his club, and lets one rip. During the contact of the golf club with the golf ball, the force of the club on the ball is ____ the force of the ball on the club and the acceleration of the club is ____ than the acceleration of the ball. i. equal to, less than For every action, there is an equal and opposite reaction force. In this case, the force on the club is equal to the force on the ball. The subsequent accelerations of the interacting objects will be inversely dependent upon mass. The more massive club will have less acceleration than the less massive ball. SP1a,d

55. Each one of Newton's Laws can play a role in any one particular situation. However, one of the laws is often most obviously dominant in governing the motion of a situation. Pick which of Newton's most governs the situations described below. A helicopter must have two sets of blades in order to fly with stability. If you were in an elevator and the cable broke, jumping up just before the elevator hit the ground would not save you. Sorry. You usually jerk a paper towel from a roll in order to tear it instead of pulling it smoothly. SP1a,d

55. d. A student desk changes the amount of force it puts on other objects throughout a school day. e. Heavy objects are not easier to move around in a horizontal fashion on the Moon than on the Earth. f. The stronger, heavier team in a tug-of-war does not create a larger tension in the rope than the weaker, lighter team. SP1a,d

55. a. A helicopter must have two sets of blades in
order to fly with stability. 3rd law b. If you were in an elevator and the cable broke, jumping up just before the elevator hit the ground would not save you. Sorry. 1st law c. You usually jerk a paper towel from a roll in order to tear it instead of pulling it smoothly. 1st law d. A student desk changes the amount of force it puts on other objects throughout a school day. 3rd law Heavy objects are not easier to move around in a horizontal fashion on the Moon than on the Earth. 1st law The stronger, heavier team in a tug-of-war does not create a larger tension in the rope than the weaker, lighter team. 3rd law SP1a,d

56. For the next several questions,
consider the velocity-time plot below for the motion of an object along a horizontal surface. The motion is divided into several time intervals, each labeled with a letter. SP1a,d

During which time interval(s), if any,
are there no forces acting upon the object? List all that apply. SP1a,d

56b. During which time interval(s), if any, are the forces acting upon the object balanced? List all that apply. SP1a,d

is there a net force acting upon the object? List all that apply. SP1a,d

During which time interval(s), if any, is the
net force acting upon the object directed toward the right? List all that apply SP1a,d

During which time interval(s), if any, is the
net force acting upon the object directed toward the left? List all that apply. SP1a,d

SP1a,d 56 answers None - If an object is on a surface, one can be
guaranteed of at least two forces – gravity and normal force. b. BDFH - If the forces are balanced, then an object is moving with a constant velocity. This is represented by a horizontal line on a velocity-time plot. c. ACEG - If an object has a net force upon it, then it is accelerating. Acceleration is represented by a sloped line on a velocity-time plot. d. AE - If the net force is directed to the right, then the acceleration is to the right (in the + direction). This is represented by a line with a + slope (i.e., upward slope). e. CG - If the net force is directed to the left, then the acceleration is to the left (in the - direction). This is represented by a line with a - slope (i.e., downward slope). SP1a,d

57.Which of the following statements are true about momentum?
a. Momentum is a vector quantity. b. The standard unit on momentum is the Joule. c. An object with mass will have momentum. d. An object which is moving at a constant speed has momentum. e. An object can be traveling eastward and slowing down; its momentum is westward. SP3c

f. Momentum is a conserved quantity; the momentum of an object is never changed.
g. The momentum of an object varies directly with the speed of the object. h. Two objects of different mass are moving at the same speed; the more massive object will have the greatest momentum. SP3c

k. An object with a changing speed will have a changing momentum.
i. A less massive object can never have more momentum than a more massive object. j. Two identical objects are moving in opposite directions at the same speed. The forward moving object will have the greatest momentum. k. An object with a changing speed will have a changing momentum. SP3c

57.Which of the following statements are true about momentum?
a. Momentum is a vector quantity.TRUE b. The standard unit on momentum is the Joule. FALSE c. An object with mass will have momentum. FALSE d. An object which is moving at a constant speed has momentum. TRUE e. An object can be traveling eastward and slowing down; its momentum is westward. FALSE SP3c

f. Momentum is a conserved quantity; the momentum of an object is never changed. FALSE
g. The momentum of an object varies directly with the speed of the object. TRUE h. Two objects of different mass are moving at the same speed; the more massive object will have the greatest momentum. TRUE SP3c

k. An object with a changing speed will have a changing momentum. TRUE
i. A less massive object can never have more momentum than a more massive object. FALSE j. Two identical objects are moving in opposite directions at the same speed. The forward moving object will have the greatest momentum. FALSE k. An object with a changing speed will have a changing momentum. TRUE SP3c

Which undergoes the greater change is momentum?
58. Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater change is momentum? Which undergoes the greater force? Which undergoes the greater impulse? Which undergoes the greater acceleration? a. the moth b.the car c.both the same SP3c

Which undergoes the greater change is momentum? C
58. Suppose that you're driving down the highway and a moth crashes into the windshield of your car. Which undergoes the greater change is momentum? C Which undergoes the greater force? C Which undergoes the greater impulse? C Which undergoes the greater acceleration? A a. the moth b.the car c.both the same SP3c

59. Which of the following statements are true about impulse?
a. Impulse is a force. b. Impulse is a vector quantity. An object which is traveling east would experience a westward directed impulse in a collision d. Objects involved in collisions encounter impulses. e. The Newton is the unit for impulse. SP3c

59f. The kgm/s is equivalent to the units on impulse.
g. An object which experiences a net impulse will definitely experience a momentum change. h. In a collision, the net impulse experienced by an object is equal to its momentum change. i. A force of 100 N acting for 0.1 seconds would provide an equivalent impulse as a force of 5 N acting for 2.0 seconds SP3c

59. Which of the following statements are true about impulse?
a. Impulse is a force. FALSE b. Impulse is a vector quantity. TRUE An object which is traveling east would experience a westward directed impulse in a collision. FALSE d. Objects involved in collisions encounter impulses. TRUE The Newton is the unit for impulse. FALSE SP3c

59f. The kgm/s is equivalent to the units on impulse. TRUE
g. An object which experiences a net impulse will definitely experience a momentum change. TRUE h. In a collision, the net impulse experienced by an object is equal to its momentum change. TRUE i. A force of 100 N acting for 0.1 seconds would provide an equivalent impulse as a force of 5 N acting for 2.0 seconds. TRUE SP3c

60. Which of the following statements are true about collisions?
a. Two colliding objects will exert equal forces upon each other even if their mass is significantly different. b. During a collision, an object always encounters an impulse and a change in momentum. c. During a collision, the impulse which an object experiences is equal to its velocity change. SP3c

60. d. The velocity change of two respective objects involved in a collision will always be equal.
e. While individual objects may change their velocity during a collision, the overall or total velocity of the colliding objects is conserved. f. In a collision, the two colliding objects could have different acceleration values. SP3c

60. g. In a collision between two objects of identical mass, the acceleration values could be different. h. Total momentum is always conserved between any two objects involved in a collision. i. When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater collision force. SP3c

60 j. When a moving object collides with a stationary object of identical mass, the stationary object encounters the greater momentum change. k. A moving object collides with a stationary object; the stationary object has significantly less mass. The stationary object encounters the greater collision force. SP3c

60. A, B, and F are true. SP3c

61.Calculate the final velocity of the white ball after the collision.
SP3c

Before Collision:(6 kg)(10 m/s)+(4 kg)(4m/s) = 76 kg m/s
61. Answer: 6 m/s Before Collision:(6 kg)(10 m/s)+(4 kg)(4m/s) = 76 kg m/s After Collision: (6 kg) v + (4 kg) (10 m/s ) = (6 kg) v + 40 kg m/s (In the following steps, the units are dropped so that the algebra can be more easily followed.) 76 = 6v + 40 36 = 6v SP3c

SP3c

Answer: 7 m/s Before Collision: (4 kg)(8 m/s)+ (2 kg)(5 m/s ) =42 After Collision: (4 kg)v + (2 kg)v (In the following steps, the units are dropped so that the algebra can be more easily followed.) 42 = 6 v v = 7 m/s SP3c

62b.Calculate the final velocity of the white ball after the collision.
SP3c

62BBB.. Answer: Answer: 9 m/s
Before Collision: (3 kg)(8 m/s) + (2 kg) (-6 m/s ) = 12 kg m/s After Collision: (3 kg)(-2 m/s) + (2 kg)v = -6 kg m/s + (2 kg) v (In the following steps, the units are dropped so that the algebra can be more easily followed.) 12 = v 18 = 2v v = 9 m/s SP3c

63. Which of the following statements are true about work?
a. Work is a form of energy. b. A Watt is the standard metric unit of work. c. Units of work would be equivalent to a Newton times a meter. d. A kg•m2/s2 would be a unit of work. e. Work is a time-based quantity; it is dependent upon how fast a force displaces an object. SP3a,f,g

63. Which of the following statements are true about work?
a. Work is a form of energy. TRUE b. A Watt is the standard metric unit of work. FALSE c. Units of work would be equivalent to a Newton times a meter. TRUE d. A kg•m2/s2 would be a unit of work. TRUE e. Work is a time-based quantity; it is dependent upon how fast a force displaces an object. FALSE SP3a,f,g

a. Positive Work b. Negative Work
64. Consider the following physical situations. Identify whether the indicated force (in boldface type) does positive work, negative work or no work. a. Positive Work b. Negative Work c. No Work Description of Physical Situation +, -, or no Work a. A cable is attached to a bucket and the force of tension is used to pull the bucket out of a well. _______________ SP3a,f,g

a. Positive Work b. Negative Work
64. Consider the following physical situations. Identify whether the indicated force (in boldface type) does positive work, negative work or no work. a. Positive Work b. Negative Work c. No Work Description of Physical Situation +, -, or no Work A cable is attached to a bucket and the force of tension is used to pull the bucket out of a well. positive SP3a,f,g

64. b. Rusty Nales uses a hammer to exert an applied force upon a stubborn nail to drive it into the wall. _______________ c. Near the end of the Shockwave ride, a braking system exerts an applied force upon the coaster car to bring it to a stop. SP3a,f,g

64. b. Rusty Nales uses a hammer to exert an applied force upon a stubborn nail to drive it into the wall. positive c. Near the end of the Shockwave ride, a braking system exerts an applied force upon the coaster car to bring it to a stop. negative SP3a,f,g

64. d. The force of friction acts upon a baseball player as he slides into third base.
_______________ e. A busy spider hangs motionless from a silk thread, supported by the tension in the thread. f. In baseball, the catcher exerts an abrupt applied force upon the ball to stop it in the catcher's mitt. SP3a,f,g

64. d. The force of friction acts upon a baseball player as he slides into third base.
negative e. A busy spider hangs motionless from a silk thread, supported by the tension in the thread. no work f. In baseball, the catcher exerts an abrupt applied force upon the ball to stop it in the catcher's mitt. SP3a,f,g

64. g. In a physics lab, an applied force is exerted parallel to a plane inclined at 30-degrees in order to displace a cart up the incline. _______________ h. A pendulum bob swings from its highest position to its lowest position under the influence of the force of gravity. SP3a,f,g

64. g. In a physics lab, an applied force is exerted parallel to a plane inclined at 30-degrees in order to displace a cart up the incline. positive h. A pendulum bob swings from its highest position to its lowest position under the influence of the force of gravity. SP3a,f,g

65. 510-kg roller coaster car starts at a height of 32. 0 m
kg roller coaster car starts at a height of 32.0 m. Assuming negligible energy losses to friction and air resistance, determine the PE, KE, and speed of the car at the various locations (A, B, C, D, and E) along the track. Location Height (m) PE (J) KE (J) velocity (m/s) Start ______ ______ A ______ ______ ______ B ______ ______ ______ C ______ ______ ______ D ______ ______ ______ E ______ ______ ______ F ______ ______ ______ SP3a,f,g

65. SP3a,f,g

A 221-gram ball is thrown at an angle of 17
A 221-gram ball is thrown at an angle of 17.9 degrees and a speed of 36.7 m/s from the top of a 39.8-m high cliff. Determine the impact speed of the ball when it strikes the ground. Assume negligible air resistance. SP3a,f,g

KEi + PEi = KEf + PEf 0.5mvi2 + mghi = 0.5mvf2 + 0
0.5 vi2 + g hi = 0.5 vf2 0.5(36.7m/s)2+(9.8 m/s/s)(39.8 m) = 0.5 vf2 673.4 m2/s m2/s2 = 0.5 vf2 1063 m2/s2 = 0.5 vf2 2127 m2/s2 = vf2 vf = 46.1 m/s SP3a,f,g

d. more than 200 e. none of these
67. Luke Autbeloe stands on the edge of a roof throws a ball downward. It strikes the ground with 100 J of kinetic energy. Luke now throws another identical ball upward with the same initial speed, and this too falls to the ground. Neglecting air resistance, the second ball hits the ground with a kinetic energy of ____ J. a. less than 100 b c. 200 d. more than 200 e. none of these SP3a,f,g

67. Luke Autbeloe stands on the edge of a roof throws a ball downward
67. Luke Autbeloe stands on the edge of a roof throws a ball downward. It strikes the ground with 100 J of kinetic energy. Luke now throws another identical ball upward with the same initial speed, and this too falls to the ground. Neglecting air resistance, the second ball hits the ground with a kinetic energy of ____ J. b. 100 SP3a,f,g

68. A 50-kg platform diver hits the water below with a kinetic energy of 5000 Joules. The height (relative to the water) from which the diver dove was approximately ____ meters. a. 5 b. 10 c. 50 d. 100 SP3a,f,g

68. Answer: B The kinetic energy of the diver upon striking the water must be equal to the original potential energy. Thus, m*g*hi = KEf (50 kg)*(~10 m/s/s)*h = 5000 J So, h = ~10 m SP3a,f,g

energy, work b. power, work c. work, energy d. work, power
69. A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of ____, but different amounts of ____. Pick the two words which fill in the blanks in their respective order. energy, work b. power, work c. work, energy d. work, power e. power, energy f. force, work g. power, force h. none of these SP3a,f,g

69. A job is done slowly, and an identical job is done quickly
69. A job is done slowly, and an identical job is done quickly. Both jobs require the same amount of ____, but different amounts of ____. Pick the two words which fill in the blanks in their respective order. d. work, power SP3a,f,g

70. A single disturbance that moves from point to point through a medium is called a ___.
a. period b. periodic wave c. wavelength d. pulse SP4

70. A single disturbance that moves from point to point through a medium is called a ___.
d. pulse SP4

71. If the particles of the medium are vibrating to and fro in the same direction of energy transport, then the wave is a ____ wave. a. longitudinal b. sound c. standing d. transverse SP4

71. If the particles of the medium are vibrating to and fro in the same direction of energy transport, then the wave is a ____ wave. a. longitudinal SP4

a. parallel to the line joining AD. b. along the line joining CI.
72. A transverse wave is traveling through a medium. The particles of the medium are vibrating _____. a. parallel to the line joining AD. b. along the line joining CI. c. perpendicular to the line joining AD. d. at various angles to the line CI. SP4

a. parallel to the line joining AD.
72. A transverse wave is traveling through a medium. The particles of the medium are vibrating _____. a. parallel to the line joining AD. SP4

73. What is the amplitude of the wave in the diagram below? a. 0.03 m.
b m. c m. d m. SP4

73. What is the amplitude of the wave in the diagram below? a. 0.03 m.
SP4

74.The number of cycles of a periodic wave occurring per unit time is defined as a wave's ____.
a. wavelength. b. period. c. amplitude. d. frequency. SP4

74.The number of cycles of a periodic wave occurring per unit time is defined as a wave's ____.
d. frequency. SP4

75. A periodic and repeating disturbance in a lake creates waves which emanate outward from its source to produce circular wave patterns. If the frequency of the source is 2.00 Hz and the wave speed is 5.00m/s then the distance between adjacent wave crests is ___ meter. a b c. 1.25 d. 2.50 e. 10.0 SP4

75. A periodic and repeating disturbance in a lake creates waves which emanate outward from its source to produce circular wave patterns. If the frequency of the source is 2.00 Hz and the wave speed is 5.00m/s then the distance between adjacent wave crests is ___ meter. d. 2.50 SP4

76. A period of 0.005 seconds would be equivalent to a frequency of ____ Hz.
SP4

The SI unit for frequency is hertz.
77. The number of waves generated per second by a source is called the frequency of the source. a. True b. False The SI unit for frequency is hertz. SP4

The SI unit for frequency is hertz. a. True
77. The number of waves generated per second by a source is called the frequency of the source. True The SI unit for frequency is hertz. a. True SP4

78. Doubling the frequency of a wave source (without altering the medium) doubles the speed of the waves. a. True b. False SP4

78. Doubling the frequency of a wave source (without altering the medium) doubles the speed of the waves. b. False Don't be fooled. Wave speed may equal frequency x wavelength. Yet doubling the frequency only halves the wavelength; wave speed remains the same. To change the wave speed, the medium would have to be changed. SP4

79. Constructive interference of waves occurs when two crests meet.
a. True b. False SP4

79. Constructive interference of waves occurs when two crests meet.
a. True SP4

80. Consider the standing wave pattern shown below
80. Consider the standing wave pattern shown below. A wave generated at the left end of the medium undergoes reflection at the fixed end on the right side of the medium. The number of antinodes in the diagram is _____. a. 3 b. 5 c. 6 d. 7 e. 12 SP4

80. Consider the standing wave pattern shown below
80. Consider the standing wave pattern shown below. A wave generated at the left end of the medium undergoes reflection at the fixed end on the right side of the medium. The number of antinodes in the diagram is _____. c. 6 SP4

a. A sound wave is a mechanical wave.
81. Which of the following statements are TRUE of sound waves? Identify all that apply. a. A sound wave is a mechanical wave. A sound wave is a means of transporting energy without transporting matter. Sound can travel through a vacuum. SP4

A sound wave is a transverse wave.
d. A sound wave is a pressure wave; they can be thought of as fluctuations in pressure with respect to time. A sound wave is a transverse wave. To hear the sound of a tuning fork, the tines of the fork must move air from the fork to one's ear. Most (but not all) sound waves are created by a vibrating object of some type. SP4

a. A sound wave is a mechanical wave. TRUE
81. Which of the following statements are TRUE of sound waves? Identify all that apply. a. A sound wave is a mechanical wave. TRUE A sound wave is a means of transporting energy without transporting matter. TRUE Sound can travel through a vacuum. FALSE SP4

A sound wave is a transverse wave. FALSE
d. A sound wave is a pressure wave; they can be thought of as fluctuations in pressure with respect to time. TRUE A sound wave is a transverse wave. FALSE To hear the sound of a tuning fork, the tines of the fork must move air from the fork to one's ear. FALSE Most (but not all) sound waves are created by a vibrating object of some type. FALSE SP4

82. The main factor which effects the speed of a sound wave is the ____.
amplitude of the sound wave intensity of the sound wave loudness of the sound wave properties of the medium pitch of the sound wave SP4

83. Which one of the following factors determines the pitch of a sound?
a. The amplitude of the sound wave b. The distance of the sound wave from the source c. The frequency of the sound wave d. The phase of different parts of the sound wave e. The speed of the sound wave SP4

the same number of overtones slightly different amplitudes
84. In order for two sound waves to produce audible beats, it is essential that the two waves have ____. the same amplitude the same frequency the same number of overtones slightly different amplitudes slightly different frequencies SP4

a. interference b. diffraction c. the Doppler effect. d. polarization
85. Consider the diagram below of several circular waves created at various times and locations. The diagram illustrates ____. a. interference b. diffraction c. the Doppler effect. d. polarization SP4

86. In the diagram below, a person positioned at point A would perceive __________ frequency as the person positioned at point B. a. higher b. lower c. the same SP4

87. An object is vibrating at its natural frequency
87. An object is vibrating at its natural frequency. Repeated and periodic vibrations of the same natural frequency impinge upon the vibrating object and the amplitude of its vibrations are observed to increase. This phenomenon is known as ____. beats fundamental interference overtone resonance SP4

88. Light usually vibrates in multiple vibrational planes
88. Light usually vibrates in multiple vibrational planes. It can be transformed into light vibrating in a single plane of vibration. The process of doing this is known as ____. a. translation b. interference c. polarization d. refraction SP4

89. Light is passed through a Polaroid filter whose transmission axis is aligned horizontally. This will have the effect of ____. a. making the light one-half as intense and aligning the vibrations into a single plane. b. aligning the vibrations into a single plane without any effect on its intensity. c. merely making the light one-half as intense; the vibrations would be in every direction. SP4

90. Consider the three pairs of sunglasses to the right
90. Consider the three pairs of sunglasses to the right. Which pair of glasses is capable of eliminating the glare from a road surface? (The transmission axes are shown by the straight lines.) SP4

90. Consider the three pairs of sunglasses to the right
90. Consider the three pairs of sunglasses to the right. Which pair of glasses is capable of eliminating the glare from a road surface? (The transmission axes are shown by the straight lines.) Answer C SP4

91. The three primary colors of light are ____. white, black, grey
blue, green, yellow red, blue, green red, blue, yellow nonsense, there are more that three primary colors. SP4

91. The three primary colors of light are ____.
a. white, black, grey b. blue, green, yellow c. red, blue, green d. red, blue, yellow e. nonsense, there are more that three primary colors. Answer C SP4

d. Red + Blue + Green = _____
92. Demonstrate your understanding of color addition by completing the following color equations. Select colors from the Color Table. a. Red + Blue = _____ b. Red + Green = _____ c. Green + Blue = _____ d. Red + Blue + Green = _____ SP4

d. White - Blue - Green = _____ e. White - Yellow = _____
93. Demonstrate your understanding of color subtraction by completing the following color equations. a. White - Blue = _____ b. White - Red = _____ c. White - Green = _____ d. White - Blue - Green = _____ e. White - Yellow = _____ SP4

a. White - Blue = R+G+B - B = R+G = Yellow
93. Demonstrate your understanding of color subtraction by completing the following color equations. a. White - Blue = R+G+B - B = R+G = Yellow b. White - Red = R+B+G - R = G+B = cyan c. White - Green = R+G+B - G = R+B = magenta d. White - Blue - Green = R+G+B - B - G = R = red e. White - Yellow = R+G+B - R+G = B = blue SP4

f. Red + Green - Green = _____ g. Yellow - Green = _____
93. Demonstrate your understanding of color subtraction by completing the following color equations. Select colors from the Color Table at the right. f. Red + Green - Green = _____ g. Yellow - Green = _____ h. Yellow - Red = _____ i. White - Magenta = _____ j. White - Cyan = _____ SP4

f. Red + Green - Green = R + G - G = R = red
93. Demonstrate your understanding of color subtraction by completing the following color equations. f. Red + Green - Green = R + G - G = R = red g. Yellow - Green = R+G - G = R = red (Note the similarity to part f.) h. Yellow - Red = R+G - R = G = green i. White - Magenta = R+G+B - R+B = G = green j. White - Cyan = R+G+B - G+B = R = red SP4

k. Yellow + Blue - Cyan = _____ l. Yellow + Cyan + Magenta = _____
93 con’t. Demonstrate your understanding of color subtraction by completing the following color equations k. Yellow + Blue - Cyan = _____ l. Yellow + Cyan + Magenta = _____ m. Yellow + Cyan - Magenta = _____ n. Yellow + Cyan - Blue - Red = _____ SP4

m. Yellow + Cyan - Magenta = R+G + B+G - R+B = G+G = green
93 con’t. Demonstrate your understanding of color subtraction by completing the following color equations. k. Yellow + Blue - Cyan = R+G + B - G+B = R = red l. Yellow + Cyan + Magenta = R+G + B+G + R+B = R+R+G+G+B+B = white + white (that is very bright white since there is double the red, green and blue added together) m. Yellow + Cyan - Magenta = R+G + B+G - R+B = G+G = green n. Yellow + Cyan - Blue - Red = R+G + G+B - B - R = G+G = green SP4

94. A filter serves the function of ____.
a. subtracting color(s) from the light which is incident upon it b. adding color(s) to the light which is incident upon it c. removing nicotine from light so that we can live longer lives . SP4

95. Which of the following are true of static charges
95. Which of the following are true of static charges? Choose all that apply. a. Like charges repel. b. Like charges attract. c. Opposite charges repel. d. Opposite charges attract. e. A positively charged object has lost electrons. f. A positively charged object has gained protons. g. A negatively charged object has lost protons. h. A negatively charged object has gained electrons SP5

96. Do # 51 p. 663 in your text

97. A neutral plastic strip is rubbed with cotton and acquires a positive charge. Which of the following statements are true of the positively-charged strip? a. It lost some electrons to the cotton during the charging process. b. It lost all of its electrons to the cotton during the charging process. c. It has the opposite charge as the cotton. d. It would now be repelled by the piece of cotton which was used to charge it. e. It gained protons during the rubbing process SP5

f. As a material, plastic has a greater affinity for electrons than cotton.
g. It could exert either a repulsive or attractive influence upon neutral paper bits. h. It has an excess of protons compared to the number of electrons. i. It could be used to charge an electroscope negatively by the process of induction. SP5

j. It lost negative electrons and gained positive electrons during the charging process.
k. It lost neutrons during the charging process (or at the very least, its neutrons became ineffective). SP5

97. A neutral plastic strip is rubbed with cotton and acquires a positive charge. Which of the following statements are true of the positively-charged strip? a. It lost some electrons to the cotton during the charging process. b. It lost all of its electrons to the cotton during the charging process. c. It has the opposite charge as the cotton. d. It would now be repelled by the piece of cotton which was used to charge it. e. It gained protons during the rubbing process SP5

f. As a material, plastic has a greater affinity for electrons than cotton.
g. It could exert either a repulsive or attractive influence upon neutral paper bits. h. It has an excess of protons compared to the number of electrons. i. It could be used to charge an electroscope negatively by the process of induction. SP5

j. It lost negative electrons and gained positive electrons during the charging process.
k. It lost neutrons during the charging process (or at the very least, its neutrons became ineffective). SP5

98. The two resistors shown are connected to identical power sources
98. The two resistors shown are connected to identical power sources. Resistor 1 has a resistance of 30Ω, and resistor 2 has a resistance of 45 Ω. The current in resistor 1 is 2 A. What is the current in resistor 2? A. 1.0 A B. 1.3 A C. 1.5 A D. 3.0 A

99. Which of the following actions would increase the current through a circuit component? A. decreasing the power in the component B. increasing the resistance of the component C. increasing the voltage across the component D. placing another identical component in series in the circuit

100. A microwave oven uses 10 A of current when connected to a wall outlet that provides 120 V of electricity. What is the resistance of the microwave oven? A Ω B. 12 Ω C. 110 Ω D Ω

101. Which of the following statements are true about an electric circuit? List all that apply.
a. Electrons are the mobile charge carriers in an electric circuit. b. The path of charge flow from the + to the - terminal of the circuit can consist of nonconductive material.

c. In an electric circuit of an automobile, the 12-Volt car battery is sometimes referred to as the internal circuit because it is located inside of the hood of the car. d. Charge is supplied with energy in the internal circuit and the energy is transformed into other forms in the external circuit.

e. Charge is consumed as it moves through the energy-transforming devices of the external circuit. For instance, the amount of charge entering a light bulb in a second is less than that which exits the light bulb in a second. f. A battery is used to power a flashlight circuit. When the battery no longer works, it is because it has run out of charge.

g. The location on an electric circuit where the charge possesses the greatest amount of electric potential energy is the + terminal of the battery.

102. Which of the following statements are true about electric current
102. Which of the following statements are true about electric current? List all that apply. a. Electric current is measured in units of Amperes. b. Electric current and drift speed are synonymous terms. c. Electric current is defined as the number of Coulombs of charge which move past a point on a circuit.

d. Electric current is equal to the number of Coulombs of charge which move past a point on a circuit per unit of time. e. Electric current provides a measure of how fast charge moves between two points on a circuit. f. The electric current diminishes in value as charge progresses to locations further and further from the + terminal of the battery.

g. The electric current in a circuit will increase as the electric potential impressed across a circuit is increased. h. The electric current in a circuit will triple in value as the electric potential impressed across a circuit is increased by a factor of three.

i. Suppose a miniature light bulb is connected to a battery in a circuit. A light bulb with a greater resistance will have a greater current. j. Wider conducting wires are capable of carrying larger currents.

k. If one starts getting technical about the meaning of electric current, one could argue that electric current is not something that flows past a point on a circuit, but rather something that exists to a given measure at a point on a circuit.

103. A negatively-charged balloon is brought near to (without touching) a neutral electroscope. With the negatively-charged balloon held near, the electroscope is momentarily touched by a hand (ground). The balloon is then removed and the needle deflects, thus showing a charge. Which of the following statements are true of the charged electroscope?

a. The electroscope was charged by the method of induction.
b. The charge on the electroscope is the same type of the charge on the balloon. c. The electroscope has more protons than electrons. d. The electroscope gained protons during the charging process.

103. a. The electroscope was charged by the method of induction.
b. The charge on the electroscope is the same type of the charge on the balloon. c. The electroscope has more protons than electrons. d. The electroscope gained protons during the charging process.

e. The electroscope gained electrons during the charging process.
f. The electroscope lost all of its electrons during the charging process. g. The electroscope lost some electrons during the charging process. h. During the charging process, protons moved from the electroscope to the balloon.

i. During the charging process, electrons moved from the electroscope to the balloon.
j. During the charging process, electrons moved from the electroscope to the hand (ground). k. During the charging process, electrons moved from the hand (ground) to the electroscope.

104. Which of the following statements are true about an electric resistance? List all that apply.
a. The resistance of an electric circuit is a measure of the overall amount of hindrance to the flow of charge through the circuit. b. A large resistance value indicates that the charge is encountering a relatively large amount of difficulty in moving through the circuit.

c. The unit of resistance is the ampere.
d. A 5-ohm resistor would allow a current of 0.5 Amperes when 2.5 Volts is impressed across it. e. A 10-ohm resistor would allow a current of 2 Amperes when 5 Volts is impressed across it. f. The resistance of a conducting wire will increase as the length of the wire is increased.

g. The resistance of a conducting wire will increase as the cross-sectional area of the wire is increased. h. Increasing the resistance of an electric circuit will cause the current in the circuit to increase. i. A threefold increase in the resistance of an electric circuit will result in a threefold decrease in the electric current.

j. A miniature light bulb with a specific resistance is connected to a 1.5-Volt battery to form a circuit. If it were connected to a 6-Volt battery instead, its resistance would increase by a factor of 4.

105. Which of the following statements are true about electric power and electric potential energy? List all that apply. a. Power is the amount of energy used by an electrical appliance. b. Power is the rate at which energy is used by an electric circuit. c. A kiloWatthour is a unit of electric power.

d. A Joule/second is a unit of power.
e. A 60-Watt light bulb would consume 30 Joules of electrical energy in 2 seconds. f. A 120-Watt light bulb would consume 1200 Joules of electrical energy in 6 seconds.

g. A charge moving through an electric circuit would gain electric potential energy in the internal circuit and lose electric potential energy in the external circuit. h. Charge has the greatest amount of electric potential energy at the - terminal of the battery. i. If a 60-Watt light bulb is placed in a 120-Volt circuit, then the current in the light bulb is 2 Amps.

j. Consider two light bulbs with different power ratings
j. Consider two light bulbs with different power ratings. A 60-Watt light bulb has a greater resistance than a 100-Watt light bulb.

106. Which of the following statements are true about a series circuit
106. Which of the following statements are true about a series circuit? List all that apply. a. Series circuits are characterized by the fact that there is a single pathway by which charge can travel from the + terminal to the - terminal. b. During any single loop of charge around a series circuit, the charge will pass through each resistor in the circuit.

c. The overall resistance of a circuit increases as more and more resistors are placed in series in the circuit. d. The total current in a circuit increases as more and more resistors are placed in series in the circuit. e. Suppose that three identical resistors with a resistance of 3-ohms are placed in series with a 12-Volt battery. The current in the circuit is 4 Amps.

f. Suppose that three identical resistors with a resistance of 3-ohms are placed in series with a 12-Volt battery. The electric potential difference across each resistor is 12 Volts. g. Suppose that two identical resistors are placed in series with a 12-Volt battery. The current in the circuit decreases with more resistors.

107. Which of the following statements are true about a parallel circuit? List all that apply.
a. Parallel circuits are characterized by the fact that there are multiple pathways by which charge can travel from the + terminal to the - terminal. b. During any single loop of charge around a parallel circuit, the charge will pass through each resistor in the circuit.

c. The overall resistance of a circuit increases as more and more resistors are placed in parallel in the circuit. d. The total current in a circuit increases as more and more resistors are placed in parallel in the circuit. e. Suppose that three identical resistors with a resistance of 3-ohms are placed in parallel with a 12-Volt battery. The current in the circuit is 1 Amp.

f. Suppose that three identical resistors with a resistance of 3-ohms are placed in parallel with a 12-Volt battery. The electric potential difference across each resistor is 12 Volts. g. Suppose that two identical resistors are placed in parallel with a 12-Volt battery. The overall current in the circuit is 6 amps. The resistance of each resistor is 4 ohms.

Conceptual Physics Daily 10

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