Question

A boy of mass 50kg running 5 m/s jumps on to a 20kg trolley travelling in the same direction at 1.5m/s. Find their common velocity?

Answer 1

Hi
This is a very simple question with a simple answer.
Hope it helps!
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m1v1 + m2v2 = (M1+M2)V

M1 - mass of boy =50kg

V1 - speed of boy= 5m/s

M2 mass of trolley = 20kg

V2 - speed of trolley = 1.5 m/s

V - final velocity

Solving for v , we get , v = (250+30)/70

V = 4m/s