Q. Two equal masses $m_{1}$ and $m_{2}$ moving along the same straight line with velocities $+ 3\ m/s$ and $- 5\ m/s$ respectively collide elastically. Their velocities after the collision will be respectively
A) $+ 4\ m/s$ for both
B) $- 3\ m/s$ and $+ 5\ m/s$
C) $- 4\ m/s$ and $+ 4\ m/s$
D) $- 5\ m/s$ and $+ 3\ m/s$
Explanation
(d) As $m_{1} = m_{2}$ therefore after elastic collision velocities of masses get interchanged
$i.e.$ velocity of mass $m_{1} = - 5\ m/s$
and velocity of mass $m_{2} = + 3\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.