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.