Question

If a trolley of mass 5kg moves at 4.m/s east across a frictionless horizontal surface and a box of mass 1,5 kg is dropped onto the trolley then the trolley and the box continues to move in the same direction.calculate the impulse of the trolley.

Answer 1

$mv=(m+m_1)u,$

$u=\frac{mv}{m+m_1}=3.1~\frac ms.$