Question

A girl of mass 40kg jumps with a horizontal velocity of 5m/s on to a stationary cart with frictionless wheels. The mass of the cart is 10kg. The girl and the cart move off together in the same straight line . Calculate the velocity with which the girl and the cart move . Assume that there is no external unbalanced force working in the horizontal direction

Answer 1

4 m/s

Step-by-step explanation:

Momentum is conserved:

m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂

(40 kg) (5 m/s) + (10 kg) (0 m/s) = (40 kg) v + (10 kg) v

200 kgm/s = 50 kg v

v = 4 m/s