- #1
JayK
- 2
- 0
Homework Statement
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?
Homework Equations
m1v1+m2v2=m1v1'+m2v2'
Fnet=ma
Ffr=(coefficient of friction)(Fn)
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.