Question

A 43.0-kg boy, riding a 2.20-kg skateboard at a velocity of 5.30 m/s across a level sidewalk, jumps forward to leap over a wall. Just after leaving contact with the board, the boy's velocity relative to the sidewalk is 6.00 m/s, 8.00° above the horizontal. Ignore any friction between the skateboard and the sidewalk. What is the skateboard's velocity relative to the sidewalk at this instant?

Answer 1

The boy is imparting an impulse with his jump which we know nothing about.