a 58kg skier is coasting down a 25degree slope with a kinetic friction force of 70N. initial speed is 3.6 m/s and distance traveled is 57m. find final velocity?

Question

a 58kg skier is coasting down a 25degree slope with a kinetic friction force of 70N. initial speed is 3.6 m/s and distance traveled is 57m. find final velocity?
 i need some help on this i don't know where to start.  
i know  W=F x cos theta x distance
is the anwser 266.27?

bobpursley · Answer

I would use energy concepts. The gravitation force down the hill is mgSinTheta.
So the change in PEnergy is mgSinTheta*57

Now, write the energy equation:
Initial PE=Final KE + friction work
mg*57*sin25= 1/2 m v^2 + 70*57

Check my thinking

natali · Answer

is the answer 18.3m/s? i just wanna make sure i did the problem right