1. Review of Momentum and Forces

2. What is the mass of a 10 kg rock on the Earth?

3. What is the net force? 20 N 10 N 20 N 10 N

4. What is the acceleration? 30 N 15 N 5 kg

5. What is the weight? 45 kg

6. What is the impulse of the 1000 kg car? 30 m/s10 m/s BeforeAfter

7. What is the normal force? m = 4 kg 30 N w FNFN f

8. What is the  ? 30,000 N FNFN f = 12,000 N

9. What is the force reading on the scale? 2 kg

10. What is the momentum of the 20 kg child? 10 m/s

11. What is the  p of the 1000 kg car? 5 m/s25 m/s BeforeAfter

12. What is the acceleration of the car? 5 m/s25 m/s BeforeAfter After 5 seconds

13. What does the safety belt do to protect Kermie?

14. A 2 kg wooden sphere and a 10 kg lead sphere of the same size are dropped from a tower. Which one has the greater  p during the fall?

15. A 2 kg cart produces the graph shown below. What is the momentum of the cart at t = 2 s?

16. A 2 kg cart produces the graph below. What is the  p for this cart during the first 3 s?

17. What is the net force acting on the 2 kg cart over the first 3 s?

18. A 2 kg cart produces the graph below. What is its momentum at t = 7 s? 0 30 60 012345678910101 1212 1313 1414 1515 1616 1717 1818 1919 2020 Time (sec) Velocity (m/s)

19. What is the momentum of the 2 kg cart at t = 14 s? 0 30 60 012345678910101 1212 1313 1414 1515 1616 1717 1818 1919 2020 Time (sec) Velocity (m/s)

20. What is the impulse for the 2 kg cart between t = 9 s and t = 11 s? 0 30 60 012345678910101 1212 1313 1414 1515 1616 1717 1818 1919 2020 Time (sec) Velocity (m/s)

21. What is the acceleration of the cart from t = 0 to t = 5 s? 0 30 60 012345678910101 1212 1313 1414 1515 1616 1717 1818 1919 2020 Time (sec) Velocity (m/s)

22. What is the displacement of the cart during the first 5 s? 0 30 60 012345678910101 1212 1313 1414 1515 1616 1717 1818 1919 2020 Time (sec) Velocity (m/s)

23. A ball on a string is whirled around someone’s head in a counterclockwise circle as seen from above. The string breaks when the ball is at the position shown. What is the path of the ball after the string breaks?

24. If Sally and Sam have the same mass, which one has the greater momentum? 0 0 position time Sam Sally

25. If Sam has a mass of 50 kg, what is his momentum at t = 4 s? position (m) time (s) Sam 16 24 6 8 10 12 14 18 0 8 16 24 32 0

26. A 0.2 kg baseball moving at 20 m/s is caught and stopped in 2 s. What is the  p of the ball?

27. A 0.2 kg baseball moving at 20 m/s is caught and stopped in 2 s. What is the F net acting on the ball?

28. A 100 kg snowball moving at 5 m/s strikes a 40 kg man moving at 2 m/s. What is the final speed of the snowball and man after the collision?

29. A 0.5 kg arrow moving at 40 m/s strikes a target and stops in 0.3 s. What is the  p of the arrow?

30. A 0.5 kg arrow strikes a target and experiences an impulse of –20 kg  m/s as it stops in 0.3 s. What is the F net acting on the arrow?