Question

Two identical balls each of mass in are moving in opposite direction with a speed v. if they collide elastically maximum potentail energy stored in the ball is :

• A. 0
• B. $\frac{1}{2}{mv}^2$
• C. ${mv}^2$
• D. $2{mv}^2$

Answer 1

The correct option is A 0

Net momentum before collision will be $mv+(-mv)=0$, $negative$ because from $opposite$ direction.

so after the collision they will get stopped to make the net momentum again $zero$ and whole energy will be get stored

as $PE$. ($inelastic$ $collision$)

There is one other possibility too that is they $exchange$ their velocities so that again the net momentum will become

$zero.$ $elastic$ $collision$ .

In elastic collision there is no loss in $KE$ so $no$ storage of $PE.$