JEE Main Physics question
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 the opposite direction with a velocity of 4 ms⁻¹. After collision the two bodies stick together and move with a common velocity which, in ms⁻¹, is equal to
Answer: (C)
Solution
Momentum conservation (taking the 2 kg body's direction as positive): 2(3) − 1(4) = 3v ⟹ 2 = 3v ⟹ v = 2/3 ms⁻¹.
## 6.0 Work, Energy and Power