Question

12. A boy of mass 50 kg running 5m/s jumps on to a 20kg trolley

travelling in the same direction at 1.5m/s. Find their common
velocity. Assume that there is no external unbalanced force
working in the horizontal direction.​

Answer 1

4 m/s

Step-by-step explanation:

Momentum is conserved.

m₁ v₁ + m₂ v₂ = (m₁ + m₂) v

(50)(5) + (20)(1.5) = (50 + 20) v

v = 4

The final velocity is 4 m/s.