Nonconservative Force Question- !

  • #1
Nonconservative Force Question--URGENT!

A skier traveling 12 m/s reaches the foot of a steady upward 18 degree incline and glides 12.2 meters up along this slope before coming to rest. What was the average coefficient of friction?


Work nonconservative= mechanicalenergyfinal-mechanicalenergyinitial

SO
Wnc= (1/2mvf^2+mghf)- (1/2mvi^2-mghi)

i used Ff= force of friction, and 3.7 coming from sin 18= (x/12.2)- 3.7 is the height of the incline plane.
m= mass

Ff*12.2= (9.8)(3.7)m-(1/2(12.0^2))m

and got Ff(12.2)= 35.74 m

so Ff= 2.92m, which means the coefficient of friction, u= 2.92m/9.8mcos18, the masses then cancelling out.

my question is, do you have to take the x-component of weight into account at all? does it affect the force of friction and thus the coefficient of friction? or do you just ignore the x-compent of weight, mgsin18?

any help would be very much appreciated, i've been debating this all weekend- thank you in advance!
 
Last edited:

Answers and Replies

  • #2
learningphysics
Homework Helper
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Looks to me like everything is correct.
 
  • #3
thank you very much, learningphysics! you have no idea how much better that makes me feel- i have a test tomorrow in ap physics! :-) thats what i thought, i just wasn't sure and i KNOW there'll be a problem like that on the test..
 

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