Question

A body moves with uniform speed of \( 20 \text{ ms}^{-1} \) in a horizontal circle. What is the change in velocity after half revolution?

• A. \( 20 \text{ ms}^{-1} \)
• B. \( 10 \text{ ms}^{-1} \)
• C. \( 40 \text{ ms}^{-1} \)
• D. \( \frac{20}{\sqrt{2}} \text{ ms}^{-1} \)

Hint:

In circular motion, for half a revolution, the change in velocity = 2 × speed.

Answer 1

The Correct Option is C

Speed is same, but after half revolution, direction reverses
Initial velocity = \( 20 \, \text{ms}^{-1} \), Final = \( -20 \, \text{ms}^{-1} \)
Change in velocity = \( |-20 - 20| = 40 \, \text{ms}^{-1} \)