1. Force & Motion

2. Standard
SPS8. Students will determine relationships among force, mass, and motion.
*a. Calculate velocity and acceleration.
b. Apply Newton’s three laws to everyday situations by explaining the following:
Inertia
Relationship between force, mass and acceleration
Equal and opposite forces
c. Relate falling objects to gravitational force
d. Explain the difference in mass and weight.
e. Calculate amounts of work and mechanical advantage using simple machines.

3. Essential Question What is the difference between speed and velocity?
What is acceleration?
How do you calculate velocity and acceleration?

4. Essential Question
What does a flat line mean on a speed/velocity graph?
What does a flat line mean on an acceleration graph?

5. Essential Question
What does the slope of a distance time graph represent?
What does the slope of a velocity/time graph represent?

6. Learning Target
YOU should understand the difference between speed and velocity and how to calculate it YOU should understand what acceleration is and how to calculate it

7. Learning Target
YOU should understand how to determine if a graph is a speed/velocity or acceleration graph.

8. An object is in motion if it changes position relative to a reference point.
Stationary objects—such as a tree, a sign, or a building—make good reference points.
The passenger can use a tree as a reference point to decide if the train is moving. A tree makes a good reference point because it is stationary from the passenger’s point of view.

9. Describing Motion
Whether or not an object is in motion depends on the reference point you choose.

10. Distance
When an object moves, it goes from point A to point B – that is the DISTANCE it traveled. (SI unit is the meter)
Distance is how much ground an object has covered during its motion. B A

11. Displacement
Knowing how far something moves is not sufficient. You must also know in what direction the object moved.
Displacement is how
far the object is from
its starting point.
You use the shortest
distance (in this case the hy hypotenuse).

12. Displacement can be 0 ! REMEMBER THIS!!!
For example, a runner starts at a certain point and runs completely around the track. If the finish line is at the original starting point, the displacement is 0 even though the runner actually ran a distance of 400 meters.

13. SPEED
Describes how fast an object
is moving.

14. Average Speed
distance
Average Speed =
time

15. Speed
Calculating Speed: If you know the distance an object travels in a certain amount of time, you can calculate the speed of the object.
What is instantaneous speed?
Instantaneous speed is the velocity of an object at a certain time.
Speed = Distance/time
Average speed = Total distance
Total time

16. Velocity The speed of an object in a certain direction
55 mph = speed
55 mph East = velocity

17. Velocity Formula Velocity = displacement time
For the formula, displacement = distance
velocity = speed

18. d Velocity V = t V = velocity (meters/second) d = distance (meters)
speed of an object in a certain direction.
V = velocity (meters/second)
d = distance (meters)
t = time (seconds)

19. Velocity
speed of an object in a certain direction.
seconds 3 1 2

20. Speed=? Velocity=? Total time= 4 seconds B 20 meters 12 meters

21. Numerator 5 12
Denominator

22. Acceleration

23. Acceleration is how quickly velocity changes over time. 3 1 2
Speed 3 1 2
Meters/second

24. Acceleration Acceleration is a change in speed or direction.
If a car is travelling at a constant speed of 55 mph, it does have a speed but the acceleration is 0 because the speed is not changing.
If the car is going around a curve at a constant speed of 25 mph, even though the speed is constant, the car is accelerating because it is changing direction.

25. (Vfinal - Vinitial) ___________ A = time Acceleration
how quickly velocity changes over time.
(Vfinal - Vinitial)
___________
A =
time

26. The graph below relates speed and time of four cars (1, 2, 3, and 4) traveling along a straight highway.
Which two cars move with zero acceleration?
1 and 4
2 and 3
1 and 2
3 and 4

27. Scalar Vector SPEED VELOCITY
A measurement that does NOT require a direction. _________ is Scalar.
SPEED
Vector
A measurement that DOES require a direction. _________ is a Vector.
VELOCITY

28. What must happen to an object in order to accelerate it?
A net force must be applied.
Some weight must be removed.
Its frictional coefficient must be reduced.
It must contain momentum.

29. Which of these describes the object with the largest acceleration ?
An object with a small change in velocity over a small change in time
An object with a small change in velocity over a large change in time
An object with a large change in velocity over a small change in time
An object with a large change in velocity over a large change in time

30. Which of the following is certain to change as a ball accelerates?
mass of the ball
inertia of the ball
velocity of the ball
force acting on the ball

31. Gravitational Magnetic
Forces of Nature
Gravitational Magnetic

32. Mass and Inertia
The universe
consists of matter
in motion

33. The greater the mass
the harder it is to move.
And . . .
the harder it is to stop moving.

34. Lower mass objects are easier to move . . .and to stop moving.

35. NEWTON’s Laws 1st Law of Motion : An object remains at a
An object remains at a
in a ,until a net force acts on it.
constant speed
straight path

36. An object will remain at a constant speed (unless disturbed).
NEWTON’s 1st Law of Motion is the law of
Inertia
ih ner shah
An object will
remain at a
constant speed
(unless disturbed).

37. the force of a moving body.
momentum
the force of a moving body.
___________
the mass times velocity of an object
p = m • v
Momentum = mass x velocity
(Kgrams) (meters/second)

38. p = m • v Momentum = mass x velocity Higher mass higher momentum
Higher velocity higher momentum
p = m • v

39. Momentum points in the direction of motion.
includes velocity.
So, it has direction.
Momentum points in the direction of motion.

40. Conservation of momentum
When objects collide, all of the momentum goes somewhere.

41. Conservation of momentum
When objects collide, all of the momentum goes somewhere.

42. When objects collide, all of the momentum goes somewhere.
Conservation of momentum
When objects collide, all of the momentum goes somewhere.

43. When objects collide, all of the momentum goes somewhere.
Conservation of momentum
When objects collide, all of the momentum goes somewhere.

44. NEWTON’s
2nd Law of Motion :
An object that has a force acting on it will change its speed (accelerate).

45. f = m•a NEWTON’s 2nd Law of Motion : f = net force (newtons)
f = m•a
force = mass • acceleration
f = net force (newtons)
m = mass (Kilograms)
a = acceleration (meters/second2)

46. f = m•a NEWTON’s 2nd Law of Motion : mass of the club
f = m•a
mass of the club
acceleration of the club
force of the club

47. Conservation of energy
NEWTON’s
3rd Law of Motion:
Conservation of energy
For every action there is
an equal and opposite reaction.

48. NEWTON’s 3rd Law of Motion: For every action, there is
For every action, there is
an equal and opposite reaction.

49. NEWTON’s 3rd Law of Motion: For every action, there is
For every action, there is
an equal and opposite reaction.

51. A car is traveling down a hill
A car is traveling down a hill. Which of the following will affect the amount of energy the car has?
how long the car is
the time of day
how much the car weighs
the color of the car

52. Oliver the dog doesn't want to walk in the rain
Oliver the dog doesn't want to walk in the rain. He can make his owner pull harder on the leash to get him out the door by sitting on the vinyl floor. sitting on the tile floor. sitting on the carpeted floor. sitting on the wood floor.

53. terminal velocity gravity will accelerate an object until air resistance (friction) does not allow it to go any faster.
gravity
air resistance

54. In the absence of air resistance, which of these objects will fall at the fastest rate when dropped?
the ball with a mass of 75 kg
the ball with a mass of 25 kg
the ball with a mass of 10 kg
They all fall at the same rate.

55. Pressure is the amount of force exerted over a certain area.
Pressure = Force
Area

56. Pressure = Force (newtons)
Area (m2)
1 Pascal = 1 Newton/meter2

57. Gravitational force
Gravity

58. All objects in the universe are attracted to each other by the force of
effort.
friction.
gravity.
inertia.

59. Four pairs of objects have the masses shown below
Four pairs of objects have the masses shown below. If the objects in each pair are the same distance apart, the gravitational force between the objects in which pair is greatest?
1 kilogram and 1 kilogram
1 kilogram and 2 kilograms
2 kilograms and 1 kilogram
2 kilograms and 2 kilograms

60. As an astronaut travels from Earth to a space station orbiting Earth, what happens to her mass and weight? Her mass decreases, but her weight remains the same. Her mass increases as her weight decreases. Her mass remains the same, but her weight decreases. Her mass decreases and her weight also decreases.

61. Which hill would you slide down the fastest?
hill A
hill B
hill C
It would take the same time to slide down all of the hills.

62. 50 39.2 29.4 19.6 9.8 Projectile Motion 3 1 2 Velocity (m/s) seconds
forward downward 50
39.2
29.4
19.6
9.8
seconds 3 1 2

63. Projectile
Motion
Velocity (m/s)
forward downward 48 47 46 50 49
39.2
29.4
19.6
9.8
seconds 3 1 2

64. Simple Machines Pulley Wheel & Axle Lever Inclined plane Screw Wedge
Gear

65. Lever action
2 meters
1 meter
Force= ?
Force=13 N

66. Mechanical
Advantage= final distance
starting distance
9 meters
3 meters

67. Mechanical
Advantage= distance
distance
8 meters
2 meters

68. Which of the following is often used as a lever?
file
nail
saw
crowbar

69. The Wedge

70. calculating mechanical Advantage
A 200 pound man lifts a rock weighing 800 pounds by standing on the end of a lever. How much mechanical advantage did the lever provide ?
            
calculating
mechanical
Advantage
M.A. = 800 Kg/200 Kg = 4

71. If you wuz ‘n a
Merry-go-round
& yuz let go,
Which wayz wud yu go?

72. Satellites stay in place as they orbit because of . . .
the repeated firing of rocket boosters.
the gravitational pull of Earth.
a narrow path through the vacuum of space.
solar panels generating energy to hold them in place

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