Work, Energy and Power Test Online MCQs

1. 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)

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

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

4. A shell of mass m moving with velocity v suddenly breaks into 2 pieces. The part having mass m/3 remains stationary. The velocity of other part will be:

5. 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:

6. When a ball is thrown up vertically with velocity v₀ it reaches a maximum height of h. If one wishes to triple the maximum height then the ball should be thrown with velocity?

7. 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

8. A ball loses 15.0% of its kinetic energy when it bounces back from a concrete wall. With what speed you must throw it vertically down from a height of 12.4 m to have it bounce back to the same height (ignore air resistance)?

9. 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:

10. 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)

11. 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:

12. For inelastic collision between two spherical rigid bodies:

13. 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

14. 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:

15. Two bodies of masses m and 4m are moving with equal kinetic energy. Then the ratio of their linear momentum will be: