Work and Energy

Grade 9 Science — Work and Energy: 25 practice questions with instant scoring and explanations.

1. Which of the following is the correct definition of work in physics?
2. A box is pushed horizontally with a force of 50 N across a floor for a distance of 10 m. Calculate the work done.
3. When is work considered negative?
4. A book is lifted vertically upward. What can be said about the work done?
5. What is the work done when a force of 20 N is applied but the object does not move?
6. Kinetic energy depends on which of the following?
7. A 2 kg ball is moving at 3 m/s. What is its kinetic energy?
8. Potential energy is the energy an object possesses due to its:
9. A 5 kg object is raised to a height of 4 m. Calculate its gravitational potential energy (g = 10 m/s²).
10. The work-energy theorem states that:
11. A car moving at constant velocity has a net work done on it of:
12. Which statement about work is true?
13. A force of 15 N acts at an angle of 30° to the direction of displacement. If displacement is 6 m, what is the work done? (cos 30° ≈ 0.87)
14. An object of mass 4 kg is dropped from rest. After falling 2 m, its kinetic energy is: (g = 10 m/s²)
15. The SI unit of work and energy is:
16. When a ball is thrown upward, at the highest point:
17. Which of the following is an example of zero work?
18. An object has kinetic energy equal to its potential energy. This means:
19. A 10 kg object moving at 4 m/s has a kinetic energy of:
20. Work done by friction is always:
21. A crane lifts a 500 kg load through a height of 20 m in 10 seconds. What is the work done? (g = 10 m/s²)
22. The gravitational potential energy of an object at Earth's surface is taken as:
23. According to the work-energy theorem, if no net work is done on an object:
24. Two objects have the same kinetic energy. Which statement is correct?
25. An object moves 8 m under a constant force of 12 N in the direction opposite to the force. The work done is: