- 2018: The answer is (B) 4K.
The kinetic energy of a body is given by: K = 1/2 mv2
If the velocity of the body is doubled, the kinetic energy will be: K = 1/2 (2m) (2v)2 = 4K
- 2017: The answer is (A) zero.
Work done is the product of force and displacement. If the velocity of the particle is constant, then the net force acting on it is zero. Hence, the work done is zero.
- 2016: The answer is (A) zero.
The work done by the net force on a body is equal to the change in kinetic energy of the body. Since the body is moving with a constant speed, its kinetic energy is not changing. Hence, the work done by the net force is zero.
