Need help finding distance of skier going down a hill! Help!

  • Thread starter Mocambo
  • Start date
1. The problem statement, all variables and given/known data
A skier on a slope inclined at 4.7Degrees to the horizontal pushes on ski poles and starts down the slope. The initial speed is 2.7m/s. The coefficient of kinetic friction between skis and snow is 0.11. Determine how far the skier will slide before coming to rest.


2. Relevant equations
Mew(k) = F(k)/F(N)

v2^2 = v1^2 + 2a(d)

F=ma

I can't really think of others that would apply.


3. The attempt at a solution

At first I tried multiplying the initial velocity into the angle given to get :

2.7*(cos4.7) = 2.6909m/s

But I am not sure how to go from there, or even if I am on the right path here. I assume that acceleration of gravity will be 9.8m/s^2 so I could possibly get the Force through multiplying initial velocity into gravity :

(9.8)*(2.7(cos4.7)) = 26.37082 N

Help
 

tiny-tim

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I could possibly get the Force through multiplying initial velocity into gravity
Hi mocambo! Welcome to PF! :smile:

hmm … you're getting very confused.

Think slowly and logically.

There are two forces, not one - consider each separately.

Hint: What force is pulling the skier? How much is it?

What force is stopping the skier? How much is it?

Does either of them depend on the angle?
 
First, you should derate the velocity due to the friction. Draw a free body diagram and that should help you out.
 
What force is pulling the skier : Gravitational force : 9.8m/s^2 ?

What force is stopping the skier : Force of Friction : .11 Mew(k)

Does either of them depend on the angle: I am not sure unfortunately, possibly the force pulling the skier will depend on the angle most likely .
 

tiny-tim

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Homework Helper
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coefficient of friction

What force is stopping the skier : Force of Friction : .11 Mew(k)
(btw, if you type alt-m, it gives you "µ", instead of "Mew"!
Mew is for cats, but µ is for cool cats! :cool:)

No. µ is the coefficient of friction: that means you have to multiply it by something else. What is that?

Does either of them depend on the angle: I am not sure unfortunately, possibly the force pulling the skier will depend on the angle most likely .
Um … you need to go back to your teacher or your book and find out all about the relationship between forces and angles.
 
ok, well I just understood the question a little better and got the answer!!!

Thanks for all your help!
 

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