(i) How much momentum will a dumb-bell of mass `10kg` transfer to the floor if it falls a height of `80 cm`? Take its downward acceleration to be `10 m//s^(2)`.
(b) A girl of mass `40 kg` running at a speed of `5m//s` horizontally jumps onto a stationary cart with frictionless wheels. The mass of the cart is `3 kg`. What is her velocity as the cart starts moving?