# More Friction

1. Nov 22, 2005

### Izekid

Here it comes, I have a frictiongrade who is 0,45 A car who is driving in 18m/s and mass of the car 1200kg

For the Frictionpower it is : 0,45 * (mg) = 5,5 kN

And how do I calculate the meters the car travels until it stops?

2. Nov 22, 2005

### skeeter

initial kinetic energy - work done by friction = 0

(1/2)m(vo)^2 - f(delta x) = 0

solve for delta x

3. Nov 23, 2005

### andrevdh

Use the work-kinetic energy theorem. That is the work done by all of the forces acting on an object (or the resultant of all of these) is equal to it's change in kinetic energy:
$$W_{F_R}=\Delta K$$