Question

A particle moving in a circular path with constant speed has:

• A. No acceleration
• B. Centripetal acceleration
• C. Zero net force
• D. Constant angular momentum

Hint:

In uniform circular motion, speed is constant but direction changes, implying acceleration toward the center—this is centripetal acceleration.

Answer 1

The Correct Option is B

Even though the speed of the particle is constant, its direction changes continuously as it moves in a circular path.
This change in direction means that the velocity vector is changing, and any change in velocity constitutes acceleration.
This acceleration is called centripetal acceleration, and it always points towards the center of the circular path.
It is given by the formula \( a = \frac{v^2}{r} \), where \( v \) is the speed and \( r \) is the radius of the circle.
Other options are incorrect because:
- (1) A particle in circular motion does have acceleration (centripetal).
- (3) There is a net inward force causing this acceleration, hence net force is not zero.
- (4) Angular momentum is not necessarily constant unless no external torque acts.