Kinetic friction and distance problem.

[johnf34]

Homework Statement

A car is traveling at a given velocity on a road with a coefficient of friction of 0.5 when it suddenly has to apply the brakes. Given that it travels 10 meters before coming to a stop what is the initial velocity of the car?

Homework Equations

Vi^2=Vf^2 + 2ax KE=1/2mv^2


3. The Attempt at a Solution [/b
I had some trouble with this since the mass isn't given, i supposed i had to figure out a way to relate two equations so that the mass could cancel but i had a hard time doing so. Can anybody help?

 

[barryj]

Assume a mass of m, and then use F=MA. Consider the normal force and coefficient of friction.

 

[haruspex]

Please post your working as far as you got.