2. Chapter 1 Johnny runs 5.00 km in 30.0 minutes, while Susan runs 7.00 km in 40.0 minutes. Who has the faster average speed? (Express answer in km/h) Johnny runs 5.00 km in 30.0 minutes, while Susan runs 7.00 km in 40.0 minutes. Who has the faster average speed? (Express answer in km/h) Johnny= 10 km/h Johnny= 10 km/h Susan= 10.5 km/h Susan= 10.5 km/h

3. What is the difference between average speed and instantaneous speed? What is the difference between average speed and instantaneous speed? Average speed is the speed across an entire trip, instantaneous speed is the speed you are traveling at any given moment in time. Average speed is the speed across an entire trip, instantaneous speed is the speed you are traveling at any given moment in time.

4. How is velocity different than speed? How is velocity different than speed? Velocity has a magnitude and a direction Velocity has a magnitude and a direction

5. Is it possible to change your velocity without changing your speed? Explain why or why not Is it possible to change your velocity without changing your speed? Explain why or why not Yes, if you change direction you are changing velocity Yes, if you change direction you are changing velocity

6. A car travels north for 200.0 miles. It takes 2.75 hours. What is the cars average velocity? A car travels north for 200.0 miles. It takes 2.75 hours. What is the cars average velocity? 72.7 mi/h North 72.7 mi/h North

7. What is acceleration? What is acceleration? Change in velocity per unit time Change in velocity per unit time

8. If you are accelerating at 5 m/s 2 how long will it take you to increase your speed from 15 m/s to 27 m/s? If you are accelerating at 5 m/s 2 how long will it take you to increase your speed from 15 m/s to 27 m/s? 2.4 s 2.4 s

9. A car travels 10 m in its 1 st second, 10 m in the 2 nd second, and 10 m in its 3 rd second. What is the cars acceleration? A car travels 10 m in its 1 st second, 10 m in the 2 nd second, and 10 m in its 3 rd second. What is the cars acceleration? 0 m/s 2 0 m/s 2

10. An object falls from a plane traveling at a height of 1500 m. How long will it take the object to hit the ground? An object falls from a plane traveling at a height of 1500 m. How long will it take the object to hit the ground? -1500= ½(-10m/s/s)(t 2 ) -1500= ½(-10m/s/s)(t 2 ) 17 s 17 s

11. If a freely falling object falls from rest, how fast will it be going after 7 seconds? How far will it have traveled? If a freely falling object falls from rest, how fast will it be going after 7 seconds? How far will it have traveled? -70 m/s -70 m/s -245 m -245 m

12. Chapter 3 A rock is thrown with an initial vertical velocity component of 30 m/s and an initial horizontal velocity component of 40 m/s. Assuming the launch and landing heights are the same, how long will the rock be in the air? How far will the rock land from where it was thrown?

14. John kicks the ball and ball does projectile motion with an angle of 53º to horizontal. Its initial velocity is 10 m/s, find the maximum height it can reach, horizontal displacement and total time required for this motion.

15. What is the net force of an object whose mass is 5 kg and whose air resistance is 7.8 N? Draw a free body diagram. Then solve for acceleration. A= 42.2 N/5 kg 8.44 m/s/s 7.8 N 50 N

16. If a 5 kg object is being pushed to the left and has an acceleration of 4.7 m/s/s and a force due to friction of 5 N, what is the applied force? 4.7 m/s/s = Fnet/5 kg Fnet = 23.5 50 N 28.5N 5 N

17. Thought that the earth was the center of the universe and that an objects acceleration is dependent upon its mass Aristotle

18. Says that the acceleration produced by a net force on an object is directly proportional to the magnitude of the force, is in the same direction of the net force, and is inversely proportional to the objects mass Newton’s Second Law

19. Caused by the irregularities in an objects surface when two objects rub against each other Acts opposite of the applied force Friction

20. Acts opposite of gravity, if it were not present, an object would continually accelerate in a downward direction Normal force

21. One of the first to propose that the earth orbited around the sun Used the changes in the constellations to make predictions about the earths motion Copernicus

22. When the amount of forces acting on an object are equal and opposite each other Equilibrium

23. The amount of matter an object contains Mass

24. An objects tendency to continue doing what it is already doing Inertia

25. An object in motion will stay in motion and an object at rest will stay at rest Newton’s first law

26. Said that an objects acceleration was dependent on mass and force by dropping objects off of the tower of Pisa and proposed the first ideas behind inertia Galileo

27. For every action there is an equal and opposite reaction Newton’s third law

28. What is the momentum of a 15-kg ball rolling 5 m/s down a hill? 15 kg*5m/s= 75kgm/s

29. If a 100 kg boulder's speed increases from 2.5 m/s to 5 m/s in 3 seconds, how much force is applied to the boulder? 100 kg(5m/s- 2.5m/s)= 3s (F) F= 83.3 N

30. A 5 kg object is rolled at 6 m/s towards a 7 kg object that is at rest. If they stick together, what is the new velocity of the combined mass? 5kg*6m/s + 7kg*0 = 12 kg(Vf) Vf= 2.4 m/s

31. A 0.5 kg object is rolled at 3 m/s towards a 1 kg object that is rolled at -5 m/s. They collide and bounce off of one another. If the 0.5 kg objects new velocity is -4 m/s, what is the new velocity of the 1 kg object? 0.5kg3m/s +1kg(-5m/s) = 0.5kg(-4m/s) +1kg(v) V = -1.5 m/s

32. A 0.145 kg baseball is pitched at a batter at 90 mph. The ball is hit back the other way at 65 mph, what is the impulse of the ball? If the contact with the bat is 0.01 seconds, how much force does the bat apply to the ball? Impulse = (0.145 kg)(-65-90)= -22.475 kgm/s -22.475 kgm/s = F(0.01) F= -2247.5 N

33. Missy Diwater, the former platform diver for the Ringling Brother's Circus had a kinetic energy of 15,000 J just prior to hitting the bucket of water. If Missy's mass is 50 kg, then what is her speed? 15,000 J = ½(50 kg)v 2 24.5 m/s

34. The potential energy of a 40-kg cannon ball is 14000 J. How high was the cannon ball to have this much potential energy? 14000J = 40kg(10 m/s/s)h 35 m

35. What is the velocity of a 500-kilogram elevator that has 4,000 joules of energy? 4000 J = ½(500kg)v 2 V=4m/s

36. You must exert a force of 4.5 N on a book to slide it across a table. If you do 2.7 J of work in the process, how far have you moved the book? What is the power exerted over 10 s? 2.7J=4.5N(X) – X= 0.6 m 2.7J/10 s= 0.27Watts

38. An amusement park ride has a radius of 2.8 m. If the time of one revolution of a rider is 0.98 s, what is the speed of the rider? V= 2π(2.8m)/.98s V= 17.95 m/s