physics help please
In screeching to a halt, a car leaves skid marks that are 68 m long. The coefficient of kinetic friction between the tires and the road is μk = 0.71. How fast was the car going before the driver applied the brakes?
I really have no clue how to even start, or what equation to use. I know that s = 68m, mu = .71, and vf= 0, but past that, I'm clueless.
January 11, 2013