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