Q: A body of mass m moving at a constant velocity v hits another body of the same mass moving with a velocity v/2 but in the opposite direction and sticks to it. The common velocity after collision is
(a) v
(b) v/4
(c) 2v
(d) v/2
Ans: (b)
Sol:
Applying conservation of momentum ,
m v – m(v/2) = (m + m)v’
mv/2 = 2 m v’
v’ = v/4