PHYSICS question regarding the velocity and mass (HELP!!!)?

Question

a 41.6 kg student runs down the sidewalk and jumps with a horizontal speed of 4.34 m/s onto a stationary skateboard. the student and skateboard move down the sidewalk with a speed of 4.07 m/s

a) find the mass of the skate board in kg

b)how fast would the student have to jump to have a final speed of 6.83 m/s ? answer in m/s

PLEASE HELP!!!

Answer 1

To solve part a, solve the following equation for m

41.6*4.34 = (41.6 + m)*4.07

To solve part b, you're going to need to plug in the answer to m that you got in part a into the following equation and solve for v.

41.6*v = (41.6 + m)*6.83

Answer 2

This is an inelastic collision.

Calculate momentum p = mv before and after the collision. Before, the skateboard v is zero.