Question

a boy of mass 60 kg running at 3m/s jumps onto a trolley of mass 140 kg moving with a velocity of 1.5m/s in the same direction. what is the common velocity ?​

Answer 1

Answer:

This question is based on conservation of momentum...

initial momentum= final momentum..

common velocity means both trolley and boy moves with same velocity..

now..

initial momentum=60×3+140×1.5

=180 + 210

=390 kgm/s

final momentum=(60+140)V

200V

so on equating..

200V=390

V=390/200=1.95m/s

Explanation: