1. The problem statement, all variables and given/known data a. A skateboarder of mass 52kg is riding her 5.5kg skateboard at a speed of 4.3m/s. She jumps off her skateboard, sending the skateboard forward at a speed of 8.6m/s. what is the velocity of the skateboarder after she jumps off? b. What is the net force if it takes 1.25 for her to come to a stop? c. what is the coefficient of friction? 2. Relevant equations m1v1+m2v2=m1v1'+m2v2' Fnet=ma Ffr=(coefficient of friction)(Fn) 3. The attempt at a solution For a, what I did was, I used the first formula to figure it out, so.. (57.5)(4.3)+(5.5)(4.3)=(57.5)(v1')+(5.5)(8.6) 270.9=57.5v1'+47.3 v1'=3.9m/s Is this right? for m1 I added 52kg and 5.5kg. For b, is the initial velocity 4.3m/s and the final 3.9m/s?? I really don't get c.