Question

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

Answer 1

Hello,

Please refer to the above photo for the used process

The answer is 4 m/sec
We have used the concept of the law of conservation of momentum.

Hope this will be helping you

Answer 2

Mass of boy = m1 = 50 kg

Mass of trolley = m2 = 20 kg

Initial velocity of boy = u1 = 5 ms-1

Initial velocity of trolley = u2 = 1.5 ms-1

Final velocity =

v = m1u1 + m2u2 \ m1 + m2

50 × 5 + 20 × 1.5 ÷ 50 + 20

= 4ms-1

HOPE IT HELPS YOU!!!