Question

A boy of mass 30 kg jumps with a horizontal velocity of 3 m s-¹ onto a stationary cart with frictionless wheels. The mass of the cart is 5 kg. What is his velocity as the cart starts moving? Assume that there is no external unbalanced force working in the horizontal direction.​

Answer 1

Answer:

Given :   M  

girl

​

=40 kg           u  

girl

​

=5 m/s        M  

cart

​

=3 kg

Initial velocity of cart  u  

cart

​

=0

Let the final velocity of cart be  V.

Applying conservation of linear momentum :    P  

i

​

=P  

f

​

 

Or    M  

girl

​

u  

girl

​

+M  

cart

​

u  

cart

​

=(M  

girl

​

+M  

cart

​

)V

Or    40×5+3×0=(40+3)V

⟹ V=  

43

200

​