1. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 5. Force and Motion In this chapter we study causes of motion: Why does the windsurfer blast across the water in the way he does? The combined forces of the wind, water, and gravity accelerate him according to the principles of dynamics. Chapter Goal: To establish a connection between force and motion.

2. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Topics: Force A Short Catalog of Forces Identifying Forces What Do Forces Do? A Virtual Experiment Newton’s Second Law Newton’s First Law Free-Body Diagrams Chapter 5. Force and Motion

3. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 5. Reading Quizzes

4. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. What is a “net force?” A. The weight excluding the container B. The vector sum of all forces in a problem C. The vector sum of all forces acting on an object D. The vector force applied by a net E. The vector sum of all forces that add up to zero

5. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. What is a “net force?” A. The weight excluding the container B. The vector sum of all forces in a problem C. The vector sum of all forces acting on an object D. The vector force applied by a net E. The vector sum of all forces that add up to zero

6. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Which of the following are steps used to identify the forces acting on an object? A. Draw a closed curve around the system. B. Identify “the system” and “the environment”. C. Draw a picture of the situation. D. All of the above. E. None of the above.

7. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Which of the following are steps used to identify the forces acting on an object? A. Draw a closed curve around the system B. Identify “the system” and “the environment” C. Draw a picture of the situation D. All of the above E. None of the above

8. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Which of these is not a force discussed in this chapter? A. The tension force B. The orthogonal force C. The normal force D. The thrust force E. None of the above

9. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Which of these is not a force discussed in this chapter? A. The tension force B. The orthogonal force C. The normal force D. The thrust force E. None of the above

10. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. What is the name of a diagram used to show all forces acting on an object? A. Motion diagram B. Interaction diagram C. Free-body diagram D. Second-law diagram

11. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. What is the name of a diagram used to show all forces acting on an object? A. Motion diagram B. Interaction diagram C. Free-body diagram D. Second-law diagram

12. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 5. Basic Content and Examples

13. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. What is a force? A force is a push or a pull on an object. A force is a vector. It has both a magnitude and a direction. A force requires an agent. Something does the pushing or pulling. A force is either a contact force or a long- range force. Gravity is the only long- range force we will deal with until much later in the book.

14. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Tactics: Drawing force vectors

15. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

16. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

17. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

18. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

19. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

20. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

21. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. A Short Catalog of Forces

22. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Tactics: Identifying forces

23. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Tactics: Identifying forces

24. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.1 Forces on a bungee jumper QUESTION:

25. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.1 Forces on a bungee jumper

26. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.2 Forces on a skier QUESTION:

27. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.2 Forces on a skier

28. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.

29. Newton’s first law is also known as the law of inertia. If an object is at rest, it has a tendency to stay at rest. If it is moving, it has a tendency to continue moving with the same velocity.

30. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Tactics: Drawing a free-body diagram

31. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Tactics: Drawing a free-body diagram

32. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.4 An elevator accelerates upward

33. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.4 An elevator accelerates upward

34. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.4 An elevator accelerates upward

35. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.4 An elevator accelerates upward

36. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.5 An ice block shoots across a frozen lake

37. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.5 An ice block shoots across a frozen lake

38. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.5 An ice block shoots across a frozen lake

39. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. EXAMPLE 5.5 An ice block shoots across a frozen lake

40. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 5. Summary Slides

41. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. General Principles

42. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. General Principles

43. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Important Concepts

44. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Important Concepts

45. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Important Concepts

46. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Key Skills

47. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Key Skills

48. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Chapter 5. Clicker Questions

49. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Two of three forces exerted on an object are shown. The net force points to the left. What is the missing third force?

50. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Two of three forces exerted on an object are shown. The net force points to the left. What is the missing third force?

51. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. You’ve just kicked a rock, and it is now sliding across the ground about 2 meters in front of you. Which of these forces act on the ball? A. Gravity, acting downward B. The normal force, acting upward C. The force of the kick, acting in the direction of motion D. Friction, acting opposite the direction of motion E. A, B, and D but not C.

52. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. You’ve just kicked a rock, and it is now sliding across the ground about 2 meters in front of you. Which of these forces act on the ball? A. Gravity, acting downward B. The normal force, acting upward C. The force of the kick, acting in the direction of motion D. Friction, acting opposite the direction of motion E. A, B, and D but not C.

53. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Two rubber bands stretched the standard distance cause an object to accelerate at 2 m/s 2. Suppose another object with twice the mass is pulled by four rubber bands stretched the standard length. The acceleration of this second object is A. 16 m/s 2. B. 8 m/s 2. C. 4 m/s 2. D. 2 m/s 2. E. 1 m/s 2.

54. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Two rubber bands stretched the standard distance cause an object to accelerate at 2 m/s 2. Suppose another object with twice the mass is pulled by four rubber bands stretched the standard length. The acceleration of this second object is A. 16 m/s 2. B. 8 m/s 2. C. 4 m/s 2. D. 2 m/s 2. E. 1 m/s 2.

55. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Three forces act on an object. In which direction does the object accelerate?

56. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Three forces act on an object. In which direction does the object accelerate?

57. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. An elevator suspended by a cable is moving upward and slowing to a stop. Which free-body diagram is correct?

58. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. An elevator suspended by a cable is moving upward and slowing to a stop. Which free-body diagram is correct?