Question

Assertion: The change in kinetic energy of a particle is equal to the work done on it by the net force. Reason: Change in kinetic energy of particle is equal to the work done only in case of a system of one particle.

The graph between the resistive force F acting on a body and the distance covered by the body is shown in the figure. The mass of the body is 25 kg and initial velocity is 2 m/s. When the distance covered by the body is 4m, then what will be its kinetic energy?

A particle of mass 0.5 kg travels in a straight line with velocity v = ax^(3/2) where a = 5 unit. What is the work done by the net force during its displacement from x = 0 m to x = 2 m?

A block of mass m is kept in an elevator which starts moving downward with an acceleration a₀ as shown in figure. The block is observed by two observers A and B for a time interval t₀.