A car is moving with a velocity of 20m/s when the brakes are applied and the wheels lock (stop spinning), The car then slides to a stop in 40m. FInd the coefficient of kinitic friction between the tires and the road.
Ffriction=coefficient fo friction*N
The Attempt at a Solution
I have drawn a picture and free body diagram, but that's as far as I've gotten. I'm stuck because I don't know how to calculate the normal force with out the mass, and I don't now how to find the coefficient without N. I know the answer is 0.51, but I do not know how to get there.