- #1
Cmertin
- 58
- 0
Homework Statement
A 75Kg skier starts down a 50m high 10˚ slope. What is his speed at the bottom?
Part A: Consider skis frictionless
Part B: Assume that the coefficient of kinetic friction between the skis and the surface of the slope is µk=.05
Homework Equations
|Ff|=µk•|FN|
Fnet=-Ff+FN+Fg=0=ma
a=g•sin(ø) (pretend that chi is theta)
FN=ma•cos(ø)
Values I figured out from Part A:
The length of the slope (on the hypotenuse) is 288m
Initial velocity in both the X and Y is 0m/s
For part A, the final velocity is 31m/s (does not need to be checked)
The Attempt at a Solution
Part A:
I got part A with 31 m/s and I know it's right.
Part B:
0=Fnet=Fg+FN-Ff=ma (Newton's second law)
Ff=Fg+FN
FN=75Kg•9.81m/s2•cos(10˚)=724.6N
I think that I have to plug the normal force into the friction equation (|Ff|=µk•|FN|
) though I'm not sure if I have to and then I don't know what I would do after that.
Last edited: