A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to

(i) (ii) t (iii) (iv)

Answer: (ii) t

Mass of the body = m

Acceleration of the body = a

Using Newton’s second law of motion, the force experienced by the body is given by the equation:

F = ma

Both m and a are constants. Hence, force F will also be a constant.

F = ma = Constant … (i)

For velocity v, acceleration is given as,

Power is given by the relation:

P = F.v

Using equations (i) and (iii), we have:

P ∝ t

Hence, power is directly proportional to time.