question_answer

A particle is moving in a circle with uniform speed. It has constant:

A)  velocity                              

B)   acceleration

C)   kinetic energy                

D)   displacement

Correct Answer: C

Solution :

Key Idea: Speed is a scalar quantity, while velocity a vector quantity. When a body moves with speed v, the kinetic energy of body is                 \[K=\frac{1}{2}m{{v}^{2}}\] Since speed (magnitude of velocity) is constant throughout motion, so kinetic energy of body does not change. While velocity changes continuously, because of which acceleration and displacement also changes.