Solve Bobsled Problem: Find How Far Does It Travel Up a 30 Degree Incline

[choyphin]

Homework Statement

After a bobsled race, the sled and riders have been partially slowed down up in an icy incline, but they need to be brought to a stop. This happens on a portion of track inclined at 30 degrees that has a coefficient of kinetic friction of 0.60. The sled enters the incline at 25.0 m/s. How far does it travel along the incline before stopping?

Homework Equations

Ff=UFn
Fn=mgcosO
f=ma

The Attempt at a Solution

I couldn't find a way of doing it, since the , mass isn't given, maybe I'm overlooking something?

 

[HallsofIvy]

Take any mass you like, say 100 kg. It should cancel out in the end.

 

[choyphin]

how would you set up the equation? and also I am sort of clueless on how to find how far the sled goes... sorry.

 

[choyphin]

I got as far as finding the resultant force for the vectors, which i got was 2000N, but that's as far as i got.

 

[HallsofIvy]

I think I would be inclined to use energy rather than force.

 

[choyphin]

ok so using the formula 1/2vi^2=FG(cos 30) d
and solving for D, in which i got 88.28, would that be correct?