Laws of Motion – Newton's Third Law, Free Body Diagrams

Grade 11 Physics — Laws of Motion – Newton's Third Law, Free Body Diagrams: 25 practice questions with instant scoring and explanations.

1. Newton's third law states that:
2. Action and reaction forces act on:
3. A book resting on a table: reaction to book's weight (gravity) is:
4. When a rocket moves up, the gas is expelled:
5. A free body diagram shows:
6. The normal reaction on a body on a horizontal surface equals its weight when:
7. A person pushes a wall with 50 N. Force on person is:
8. Two blocks A (2 kg) and B (3 kg) on smooth surface with F=10 N on A pushing B. Acceleration:
9. In the above, force A exerts on B:
10. Tension in a light string attached to a 5 kg mass hanging in equilibrium (g=10 m/s²):
11. When a horse pulls a cart, the cart moves forward because:
12. A 2 kg block placed in a lift accelerating up at 2 m/s²; normal reaction is (g=10):
13. A 2 kg block in a lift accelerating down at 2 m/s²; normal reaction:
14. In a free fall, apparent weight is:
15. A stone thrown horizontally hits a wall. The wall exerts force due to:
16. If action force is 20 N, reaction force is:
17. In static equilibrium, net force equals:
18. Two masses 3 kg and 5 kg connected by a string over a frictionless pulley (Atwood). Acceleration (g=10):
19. In above Atwood, tension in string:
20. A man jumps from a boat to the shore. The boat moves backward because of:
21. On a smooth inclined plane of angle θ, acceleration of a block sliding down:
22. On a smooth inclined plane of angle θ, normal reaction on block of mass m:
23. A 2 kg block on a smooth incline of 30° accelerates at (g=10):
24. A 3 kg mass on a rope pulled up with 45 N; acceleration is (g=10):
25. In equilibrium, sum of forces on a body equals: