# Coefficient of kinetic Friction given velocity and distance.

## Homework Statement

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.

## Homework Equations

F=ma
Ffriction=coefficient fo friction*N
N=mg

## 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.

take it as m
it will get cancelled in the process.

So, basically that means the total force acting on the car is the velocity and the frictional force. After ignoring the mass though, I'm still stuck. I don't know how to find the frictional force or the coefficent of friciton when ignoring mass.

Dont ignore mass, take it as m.

Then do the general method and find the answer.
mass wont be any problem