Problem 1:  A student of mass m = 72 kg runs at a velocity vi = 1.53 m/s before jumping on a skateboard that is initially at rest. After jumping on the board the student has a velocity vf = 1.43 m/s.         33% Part (a)  Write an expression for the weight of the skateboard W in terms of the mass of the student m, the student's initial velocity vi, the final velocity of the student and board vf, and the acceleration due to gravity g. W = ( ( ( m vi )/vf ) - m ) g     ✔ Correct!

  33% Part (a)  Write an expression for the weight of the skateboard W in terms of the mass of the student m, the student's initial velocity vi, the final velocity of the student and board vf, and the acceleration due to gravity g.

  33% Part (b)  What is the mass of the skateboard in kilograms?

  33% Part (c)  The student soon loses his balance and falls backwards off the board at a velocity of 1.0 m/s. Assuming momentum is conserved in this process, what is the skateboard's new velocity in meters per second? [Note: this may not be a very good assumption, as there can be significant friction in the ball bearings of the skateboard]