Question

A body moving in a circular path with a constant speed has a constant .

• A. velocity
• B. momentum
• C. kinetic energy
• D. acceleration

Answer 1

The correct option is C kinetic energy

We can see that direction of velocity and acceleration changes continuously

$\therefore$ Both are not constant.

Momentum is m.$\overrightarrow{v}$ which depends on velocity and hence cannot be constant.

The only quantity that is constant is speed and kinetic energy, where kinetic energy is given by $\frac{1}{2}m|\overrightarrow{v}{|}^2$, where $|\overrightarrow{v}|$ is the speed.