Calculating Mechanical Energy Lost to Friction on Ski Slope

[AD_3]

Homework Statement

How much mechanical energy is lost to friction if a 58.1-kg skier slides down a ski slope at constant speed of 12.1 m/s? The slope is 122.3 m long and makes an angle of 10.3° with respect to the horizontal.

Homework Equations

Emec=KE+PE

The Attempt at a Solution

I first found the height of the slope by using sin. Then I tried calculating the difference in PE and KE but it was wrong. I don't know where to go from here.

 

[Shootertrex]

Since the the skier is moving with constant velocity, what does this tell us about the forces acting on the skier and how it relates to friction?