Mech Forces HW-32 c. Review your answer to part a. In addition, reread the portion of your physics text that discusses Newton's third law. Then consider a book on a level table: • Which force completes the Newton's third law (or action-reaction) force pair with the normal force exerted on the book by the table? • Which force completes the Newton's third law (or action-reaction) force pair with the weight of the book? Rope 3. A chain is suspended by a rope as shown at right. The chain is composed of four identical links and does not move. a. In the spaces below, draw a free-body diagram for each of the four links. Label each of the forces as you were instructed in the tutorial Forces. Free-body diagram for link I Free-body diagram for link 2 Free-body diagram Free-body diagram for link 3 for link 4 2 b. Identify all the Newton's third law (action-reaction) force pairs in your diagrams by placing one or more small "X" symbols through each member of the pair (ie., mark each member of the first pair as →→→→, each member of the second pair as, etc.). c. Rank, from largest to smallest, the magnitudes of all the forces on your diagrams. Explain your reasoning, including how you used Newton's second and third laws. ( FORCES Homework 5: Part 1 - Laws of Motion Name 1. A string is tied to a book and pulled lightly as shown at right. The book remains in contact with the table and does not move. String a. Draw a free-body diagram for the book. Label each of the forces exerted on the book as you were instructed in the tutorial Forces. Book Table b. How do the forces exerted on the book in this case compare to the forces exerted on the book when the string is not present? List any forces that are the same (ie., same type of force, same direction, and same magnitude) in both cases. Make a separate list of forces that change (or are not present) when the string is pulled. 2. a. Consider the following statement made by a student about a book at rest on a level table: "The two forces exerted on the book are the normal force directed up and the weight of the book directed down. These are equal and opposite to one another. By Newton's third law they are a third law force pair, so the normal force is always equal to the weight of the book." Do you agree with the student? Explain why you agree or disagree. b. Consider a book on top of a level table while the book is being pressed straight down by a hand. i. In the space below, draw a free-body diagram for the book. Label the forces as you did in the tutorial Forces. ii. How do the forces exerted on the book in this case compare to the forces exerted on the book when the hand is not pushing? List any forces that are the same (ie., same type of force, same direction, and same magnitude) in both cases. Make a separate list of forces that change (or are not present) when the hand is pressing down on the book. 111. Is the magnitude of the weight equal to the magnitude of the normal force exerted by the table on the book? How can you tell? Tutorials in Introductory Physics McDermott, Shaffer, & PEG.. U. Wash. CPrentice Hall, Inc. First Edition, 2002 Mech HW-31

Mech Forces HW-32 c. Review your answer to part a. In addition, reread the portion of your physics text that discusses Newton's third law. Then consider a book on a level table: • Which force completes the Newton's third law (or action-reaction) force pair with the normal force exerted on the book by the table? • Which force completes the Newton's third law (or action-reaction) force pair with the weight of the book? Rope 3. A chain is suspended by a rope as shown at right. The chain is composed of four identical links and does not move. a. In the spaces below, draw a free-body diagram for each of the four links. Label each of the forces as you were instructed in the tutorial Forces. Free-body diagram for link I Free-body diagram for link 2 Free-body diagram Free-body diagram for link 3 for link 4 2 b. Identify all the Newton's third law (action-reaction) force pairs in your diagrams by placing one or more small "X" symbols through each member of the pair (ie., mark each member of the first pair as →→→→, each member of the second pair as, etc.). c. Rank, from largest to smallest, the magnitudes of all the forces on your diagrams. Explain your reasoning, including how you used Newton's second and third laws. ( FORCES Homework 5: Part 1 - Laws of Motion Name 1. A string is tied to a book and pulled lightly as shown at right. The book remains in contact with the table and does not move. String a. Draw a free-body diagram for the book. Label each of the forces exerted on the book as you were instructed in the tutorial Forces. Book Table b. How do the forces exerted on the book in this case compare to the forces exerted on the book when the string is not present? List any forces that are the same (ie., same type of force, same direction, and same magnitude) in both cases. Make a separate list of forces that change (or are not present) when the string is pulled. 2. a. Consider the following statement made by a student about a book at rest on a level table: "The two forces exerted on the book are the normal force directed up and the weight of the book directed down. These are equal and opposite to one another. By Newton's third law they are a third law force pair, so the normal force is always equal to the weight of the book." Do you agree with the student? Explain why you agree or disagree. b. Consider a book on top of a level table while the book is being pressed straight down by a hand. i. In the space below, draw a free-body diagram for the book. Label the forces as you did in the tutorial Forces. ii. How do the forces exerted on the book in this case compare to the forces exerted on the book when the hand is not pushing? List any forces that are the same (ie., same type of force, same direction, and same magnitude) in both cases. Make a separate list of forces that change (or are not present) when the hand is pressing down on the book. 111. Is the magnitude of the weight equal to the magnitude of the normal force exerted by the table on the book? How can you tell? Tutorials in Introductory Physics McDermott, Shaffer, & PEG.. U. Wash. CPrentice Hall, Inc. First Edition, 2002 Mech HW-31