Question

A girl of mass 40 kg jumps with a horizontal velocity of 5 m/s onto a cart of mass 10kg with friction less wheels, which is already moving with a horizontal velocity 1 m/s in the opposite direction of motion of the girl. What will be the velocity of the girl, when the cart moves along with her. (Assume that there is no external unbalanced force working in the horizontal direction. NO SPAM

Answer 1

Explanation:

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