You are standing at rest and begin to walk forward. What force pushes you forward?

1. Q4.1 You are standing at rest and begin to walk forward. What force pushes you forward? 1. the force of your feet on your ground 2. the force of your acceleration 3. the force of your velocity 4. the force of your momentum 5. the force of the ground on your feet

2. A4.1 You are standing at rest and begin to walk forward. What force pushes you forward? 1. the force of your feet on your ground 2. the force of your acceleration 3. the force of your velocity 4. the force of your momentum 5. the force of the ground on your feet

3. Q4.2 An apple sits at rest on a horizontal table top. The gravitational force on the apple (its weight) is one half of an action-reaction pair. What force is the other half? 1. the force of the Earth’s gravity on the apple 2. the upward force that the table top exerts on the apple 3. the upward force that the apple exerts on the Earth 4. the downward force that the apple exerts on the table top 5. the frictional force between the apple and the table top

4. A4.2 An apple sits at rest on a horizontal table top. The gravitational force on the apple (its weight) is one half of an action-reaction pair. What force is the other half? 1. the force of the Earth’s gravity on the apple 2. the upward force that the table top exerts on the apple 3. the upward force that the apple exerts on the Earth 4. the downward force that the apple exerts on the table top 5. the frictional force between the apple and the table top

5. Q4.3 An apple sits at rest on a horizontal table top. The weight of the apple is equal to the magnitude of the upward force that the table top exerts on the apple. Why? 1. this is a consequence of Newton’s first law 2. this is a consequence of Newton’s third law 3. because we assume that the table top is perfectly rigid 4. two of the above three statements are correct 5. all of the first three statements are correct

6. A4.3 An apple sits at rest on a horizontal table top. The weight of the apple is equal to the magnitude of the upward force that the table top exerts on the apple. Why? 1. this is a consequence of Newton’s first law 2. this is a consequence of Newton’s third law 3. because we assume that the table top is perfectly rigid 4. two of the above three statements are correct 5. all of the first three statements are correct

7. Q4.4 A woman pulls on a 6.00-kg crate, which in turn is connected to a 4.00-kg crate by a light rope. The light rope remains taut. Compared to the 6.00–kg crate, the lighter 4.00-kg crate 1. is subjected to the same net force and has the same acceleration 2. is subjected to a smaller net force and has the same acceleration 3. is subjected to the same net force and has a smaller acceleration 4. is subjected to a smaller net force and has a smaller acceleration 5. none of the above

8. A4.4 A woman pulls on a 6.00-kg crate, which in turn is connected to a 4.00-kg crate by a light rope. The light rope remains taut. Compared to the 6.00–kg crate, the lighter 4.00-kg crate 1. is subjected to the same net force and has the same acceleration 2. is subjected to a smaller net force and has the same acceleration 3. is subjected to the same net force and has a smaller acceleration 4. is subjected to a smaller net force and has a smaller acceleration 5. none of the above

9. Q4.5 You are pushing a 1.00-kg food tray through the cafeteria line with a constant 9.0-N force. As the tray moves, it pushes on a 0.50-kg milk carton. If the food tray and milk carton move at constant speed, 1. the tray exerts more force on the milk carton than the milk carton exerts on the tray 2. the tray exerts less force on the milk carton than the milk carton exerts on the tray 3. the tray exerts as much force on the milk carton as the milk carton exerts on the tray

10. A4.5 You are pushing a 1.00-kg food tray through the cafeteria line with a constant 9.0-N force. As the tray moves, it pushes on a 0.50-kg milk carton. If the food tray and milk carton move at constant speed, 1. the tray exerts more force on the milk carton than the milk carton exerts on the tray 2. the tray exerts less force on the milk carton than the milk carton exerts on the tray 3. the tray exerts as much force on the milk carton as the milk carton exerts on the tray

11. Q4.6 You are pushing a 1.00-kg food tray through the cafeteria line with a constant 9.0-N force. As the tray moves, it pushes on a 0.50-kg milk carton. If the food tray and milk carton are accelerating to the left, 1. the tray exerts more force on the milk carton than the milk carton exerts on the tray 2. the tray exerts less force on the milk carton than the milk carton exerts on the tray 3. the tray exerts as much force on the milk carton as the milk carton exerts on the tray

12. A4.6 You are pushing a 1.00-kg food tray through the cafeteria line with a constant 9.0-N force. As the tray moves, it pushes on a 0.50-kg milk carton. If the food tray and milk carton are accelerating to the left, 1. the tray exerts more force on the milk carton than the milk carton exerts on the tray 2. the tray exerts less force on the milk carton than the milk carton exerts on the tray 3. the tray exerts as much force on the milk carton as the milk carton exerts on the tray

13. Q4.7 Two crates, A and B, sit at rest side-by-side on a frictionless horizontal surface. You apply a horizontal force to crate A as shown. Which statement is correct? 1. the acceleration has a greater magnitude than if B were in the back and A were in the front 2. the acceleration has a smaller magnitude than if B were in the back and A were in the front 3. the crates will not move if the force magnitude F is less than the combined weight of the two crates 4. two of the above three statements are correct 5. none of the first three statements is correct

14. A4.7 Two crates, A and B, sit at rest side-by-side on a frictionless horizontal surface. You apply a horizontal force to crate A as shown. Which statement is correct? 1. the acceleration has a greater magnitude than if B were in the back and A were in the front 2. the acceleration has a smaller magnitude than if B were in the back and A were in the front 3. the crates will not move if the force magnitude F is less than the combined weight of the two crates 4. two of the above three statements are correct 5. none of the first three statements is correct

15. Q4.8 A horse is hitched to a wagon. Which statement is correct? 1. the force the horse exerts on the wagon is greater than the force that the wagon exerts on the horse 2. the force the horse exerts on the wagon is less than the force that the wagon exerts on the horse 3. the force the horse exerts on the wagon is just as strong as the force that the wagon exerts on the horse 4. the answer depends on the velocity of horse and wagon 5. the answer depends on the acceleration of horse and wagon

16. A4.8 A horse is hitched to a wagon. Which statement is correct? 1. the force the horse exerts on the wagon is greater than the force that the wagon exerts on the horse 2. the force the horse exerts on the wagon is less than the force that the wagon exerts on the horse 3. the force the horse exerts on the wagon is just as strong as the force that the wagon exerts on the horse 4. the answer depends on the velocity of horse and wagon 5. the answer depends on the acceleration of horse and wagon