Solving Kinetic Friction: Find Coefficient of Friction from Car Stop

[mels]

Homework Statement

A car is moving with a speed of 20m/s when the brakes are applied. The wheels lock (stop spinning). After traveling 40m, the car stops. Determine the coefficient of kinetic friction between the tires and the road.

Homework Equations

Fk=uk x Fn

The Attempt at a Solution

I don't know how to encorporate the given into the equation !

 

[Platformance]

There's another equation you need, one that puts all the given data together.

 

[raghav singh]

You can apply simple formula...

calculate the acceleration 'a'... by
(square of final velocity)-(square of initial velocity)=2x a x distance

a=20x20/(2x40)
a=5

balance the force
uk x mass x g = mass x a
uk=a/g
uk=5/10=0.5

 

[mels]

okay thank you ! i really appreciate it :)