Question

A truck of mass 500 kg moving at 4 m/s collides with another truck of mass 1500 kg moving in the same direction at 2 m/s. What is their common velocity just after the collision if they move off together ?

Answer 1

Mass of first truck, m₁ = 500 kg

Speed of first truck, u₁ = 4 m/s

Mass of second truck, m₂ = 1500 kg

Speed of second truck, u₂ =2 m/s

Combined mass of both trucks, m = 1500 + 500 = 2000 kg

Combined velocity v

Acc. to the law of conservation of momentum

m₁ u₁ + m₂ u₂ = mv

500 x 4 + 1500 x 2 = 2000 x v