1. Chapter 4 Review

2. Question What is the SI unit of force?

3. Answer Newton

4. Question A 1850 kg car is moving to the right at a constant speed of 1.44 m/s. What is the net force on the car?

5. Answer Zero

6. Question What acceleration would you give a 24.3 kg box if you push it horizontally with a net force of 85.5 N?

7. Answer 3.52 m/s 2

8. Question What net force is required to give a 25 kg suitcase an acceleration of 2.2 m/s 2 to the right?

9. Answer 55 N to the right

10. Question Find the normal force acting on 5.5 kg laundry basket that is at rest on a ramp inclined at 12⁰ above the horizontal.

11. Answer 54 N

12. Question Which is usually greater, the maximum force of static friction or the force of kinetic friction?

13. Answer Maximum force due to static friction

14. Question A 95 kg clock initially at rest on a horizontal floor requires a 650 N horizontal force to set it in motion. After the clock is in motion, a horizontal force of 560 N keeps it moving with a constant velocity. Find µ s and µ k between the clock and the floor. (1 point each)

15. Answer µ s = 0.70 µ k = 0.60

16. Question A box slides down a 30.0⁰ ramp with an acceleration of 1.20 m/s 2. Determine the coefficient of kinetic friction between the box and the ramp. Be careful with direction!

17. Answer 0.436

18. Question A clerk moves a box of cans down an aisle by pulling on a strap attached to the box. The clerk pulls with a force of 185.0 N at an angle of 25.0⁰ with the horizontal. The box has a mass of 35.0 kg, and the coefficient of kinetic friction between the box and the floor is 0.450. Find the acceleration of the box.

19. Answer 1.4 m/s 2 down the aisle

20. Question What are 2 possible states of motion an object might be experiencing if it is in equilibrium? Be specific! (1 point each)

21. Answer At rest constant speed in a straight line

22. Question A smart car and a hummer collide. Which car experiences the greater force?

23. Answer Force is equal on both cars

24. Question A girl on a sled coasts down a hill. Her speed is 7.0 m/s when she reaches level ground at the bottom. The coefficient of kinetic friction between the sled’s runners and the hard, icy snow is 0.050, and the girl and the sled together weigh 645 N. How far does the sled travel on level ground before coming to a rest?

25. Answer 49 m

26. Question In what direction does the normal force ALWAYS act?

27. Answer Perpendicular to the contact surface

28. Question

29. Find the weight of the picture.

30. Answer 42.4 N

31. Question Justin Bieber runs into CeeLo Green and they collide. Who has the greater acceleration and why?

32. Answer Justin Bieber because he has a smaller mass

33. Question The sign has a mass of 10 kg. Find the tension in each cable.

34. Answer 56.6 N

35. Question A bag of sugar has a mass of 2.26 kg. What is its weight in newtons on the moon, where the acceleration due to gravity is one-sixth that of Earth?

36. Answer 3.7 N

37. Question Name one example of a field force

38. Answer Gravitational force, magnetism

39. Question A freight train has a mass of 1.5 x 10 7 kg. If the locomotive can exert a constant pull of 7.5 x 10 5 N, how long would it take to increase the speed of the train from rest to 85 km/h?

40. Answer 470 s

41. Question What is the tendency of objects to NOT accelerate called?

42. Answer inertia

43. Question What is the vector sum of all external forces acting on an object called?

44. Answer Net force

45. Question What is the SI unit of mass?

46. Answer kilogram

47. Question What is the mass of a 63 kg object on Venus where the acceleration due to gravity is 5.8 m/s²?

48. Answer 63 kg silly!