Question

A particle is acted upon by a constant power. Then, which of the following physical quantity remains constant?

• A. Speed
• B. Rate of change of acceleration
• C. Kinetic energy
• D. Rate of change of kinetic energy

Answer 1

The correct option is D Rate of change of kinetic energy

We have
Power=Rate of doing work=$\frac{dW}{dt}$
or $P=\frac{dW}{dt}=$ Rate of change in KE
ie., $P=\frac{dW}{dt}=\frac{d\left(KE\right)}{dt}$= constant

So, when power is constant, rate of change of kinetic energy is also constant.