Question

A boy of mass 30kg jumps into a stationary cart with a horizontal
velocity of 5m/s. The mass of the cart is 10kg. What is his velocity as the
cart starts moving?

Answer 1

Answer:

Given :   Mgirl=40 kg           ugirl=5 m/s        Mcart=3 kg

Initial velocity of cart  ucart=0

Let the final velocity of cart be  V.

Applying conservation of linear momentum :    Pi=Pf

Or    Mgirlugirl+Mcartucart=(Mgirl+Mcart)V

Or    40×5+3×0=(40+3)V

⟹ V=43200 m/s