Q. A big ball of mass $M$, moving with velocity $u$ strikes a small ball of mass $m$, which is at rest. Finally small ball obtains 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) $\frac{2m}{M + m}u$
D) $\frac{M}{M + m}u$
Explanation
(a) From the formulae $v_{1} = \left( \frac{m_{1} - m_{2}}{m_{1} + m_{2}} \right)u_{1}$
We get $v = \left( \frac{M - m}{M + m} \right)u$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.