Work, Energy and Power Test Online MCQs

1. A particle of mass 10 g is kept on the surface of a uniform sphere of mass 100 Kg and radius 10 cm. Find the work to be done against the gravitational force between them to take the particle far away from the sphere (you may take G = 6.67 x 10⁻¹¹ Nm² /kg²)

2. A ball of mass 10 kg is moving with a velocity of 10 m/s. It strikes another ball of mass 5 kg, which is moving in the same direction with a velocity of 4 m/s. If the collision is elastic their velocities after collision will be respectively

3. A body of mass 5 kg has momentum of 10 kg m/sec. When a force of 0.2 N is applied on it for 10 sec, the change in its kinetic energy is

4. For inelastic collision between two spherical rigid bodies:

5. A force newton acts on a body and displaced it by meter. The work done by the force is:

6. Which one of the following is true?

7. If the kinetic energy of the body becomes four times of its initial value, then the new momentum will

8. If the water falls from a dam into a turbine wheel 19.6 m below, then the velocity of water at the turbines, is (take g = 9.8 m/s²)

9. If the water falls from a dam into a turbine wheel 19.5 m below, then the velocity of water at the turbine is: (take g = 9.8 m/sec²)

10. If a spring extends by x on loading, then energy stored by the spring is (if T is the tension in spring and k is spring constant)

11. A block of mass 10 kg is moving in x-direction with a constant speed of 10 m/sec. It is subjected to a retarding force F = -0. 1x joule/meter during its travel from x = 20 meter to x = 30 meter. Its final kinetic energy will be:

12. A bullet of mass 10g leaves a riffle at an initial velocity of 1000 m/sec and strikes the earth at the same level with a velocity of 500 m/sec. The work in overcoming the resistance of air will be:

13. If the force applied is F and the velocity gained is v, then the power developed is:

14. A particle of mass m moving with velocity v collides with a stationary particle of mass 2m. Then the speed of the system after collision is:

15. A metal ball of mass 2 kg moving with speed of 36 km/hr is having a collision with a stationary ball of mass 3 kg. If after collision, both the balls move together, the loss in kinetic energy due to collision is: