Question

A boy of mass 45 kg running at 6 m/s jumps on to a trolley of mass 120 kg travelling in the same direction at 1.5 m/s. find their common velocity.

Answer 1

M1V1=M2V2 (conversation of momentum)

so 45*6=(120+45)*(v1+v2)

270=165*(1.5+v2)

270/165=1.5+v2

1.63=1.5+v2

V2=0.13