Question

In case of perfectly elastic collision,

• A. the total kinetic energy before collision is equal to the total kinetic energy after collision.
• B. the total kinetic energy before collision is less than total kinetic energy after collision.
• C. the total kinetic energy before collision is greater than the total kinetic energy after collision.
• D. coefficient of restitution is equal to zero.

Hint:

In an elastic collision kinetic energy is conserved and the coefficient of restitution is 1.

Answer 1

The Correct Option is A

Step 1: Definition
Perfectly elastic means no kinetic energy is converted to heat, sound or deformation.

Step 2: Consequence
Total kinetic energy is unchanged and $e = 1$.

Step 3: Answer
Option (A).

Final Answer:
Option (A). \[ \boxed{KE_{\text{before}} = KE_{\text{after}}} \]