(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

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 µ_{k}=.05

2. Relevant equations

|F_{f}|=µ_{k}•|F_{N}|

F_{net}=-F_{f}+F_{N}+F_{g}=0=ma

a=g•sin(ø) (pretend that chi is theta)

F_{N}=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)

3. The attempt at a solution

Part A:

I got part A with 31 m/s and I know it's right.

Part B:

0=F_{net}=F_{g}+F_{N}-F_{f}=ma (Newton's second law)

F_{f}=F_{g}+F_{N}

F_{N}=75Kg•9.81m/s^{2}•cos(10˚)=724.6N

I think that I have to plug the normal force into the friction equation (|F_{f}|=µ_{k}•|F_{N}|

) though I'm not sure if I have to and then I don't know what I would do after that.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Skier on a slope with friction (looking for final velocity)

**Physics Forums | Science Articles, Homework Help, Discussion**