Question

A big ball of mass $M$, moving with a velocity $u$ strikes a small ball of mass $m$, which is at rest. Finally, small ball attains velocity $u$ and big ball $v$. Then what is the value of $v$

• A. $\frac{M-m}{M+m}u$
• B. $\frac{m}{M+m}u$
• C. $\frac{2m}{M+m}$
• D. $\frac{M}{M+m}$

Answer 1

The correct option is A $\frac{M-m}{M+m}u$

By momentom conservation,

$Mu=Mv+mu$

$v=\frac{(M-m)u}{M}$