JEE Main Physics question
A body of mass 2 kg with velocity 3 m/sec collides head-on with a body of mass 1 kg moving in the opposite direction with velocity 4 m/sec. After collision, the two bodies stick together and move with a common velocity which, in m/sec, is equal to
Answer: (C)
Solution
By momentum conservation: 2(3) − 1(4) = (2+1)v ⟹ 2 = 3v ⟹ v = 2/3 m/s.