Finding stopping distance given coefficient of kinetic friction and mass

[disque]

Homework Statement

Bobsled

A bobsled run leads down a hill as sketched in the figure above. Between points A and D, friction is negligible. Between points D and E at the end of the run, the coefficient of kinetic friction is µk = 0.4. The mass of the bobsled with drivers is 210 kg and it starts from rest at point A.

Find the distance x beyond point D at which the bobsled will come to a halt.

Homework Equations

PE=mgy
(delta)x = ½ v_o2/ mg

The Attempt at a Solution

I thought the bottom equation should be the right approach but I don't know how to find the velocity given the coefficient of kinetic friction and mass of the sled

 

[tiny-tim]

A bobsled run leads down a hill as sketched in the figure above. Between points A and D, friction is negligible. Between points D and E at the end of the run, the coefficient of kinetic friction is µk = 0.4. The mass of the bobsled with drivers is 210 kg and it starts from rest at point A.

Find the distance x beyond point D at which the bobsled will come to a halt.

Hi disque!

(I can't see the picture yet)

This is an energy question …

calculate the the work done by friction,

and use the work-energy theorem, which says that loss of energy equals work done.