Q. A body of mass 3kg is moving with a velocity of 4$ms^{- 1}$ towards right, collides head on with a body of mass 4 kg moving in opposite direction with a velocity of 3$ms^{- 1}$. After collision the two bodies stick together and move with a common velocity, which is
A) Zero
B) 12 $ms^{- 1}$ towards left
C) 12$ms^{- 1}$ towards right
D) $\frac{12}{7}ms^{- 1}$ towards left
Explanation
(a) [image:7_image170.emf]
$m_{1}u_{1} + m_{2}u_{2} = (m_{1} + m_{2})v$
$3 \times 4 + 4 \times ( - 3) = (3 + 4)v\ \ \ v = 0$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.