Q. A body of mass $2\ kg$ moving with a velocity of $3\ m/sec$ collides head on with a body of mass $1\ kg$ moving in opposite direction with a velocity of $4\ m/sec$. After collision, two bodies stick together and move with a common velocity which in $m/sec$ is equal to
A) $1/4$
B) $1/3$
C) $2/3$
D) $3/4$
Explanation
(c) $m_{1}v_{1} - m_{2}v_{2} = \left( m_{1} + m_{2} \right)v$
$\Rightarrow 2 \times 3 - 1 \times 4 = (2 + 1)v$
$\Rightarrow v = \frac{2}{3}\ m/s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.