9) A policeman investigating an accident measures the skid marks left by a car. He determines that 9) the distance between the point that the driver slammed on the brakes and the point where the car came to a stop was 28.0 m. From a reference manual he determines that the coefficient of kinetic friction between the tires and the road under the prevailing conditions was 0.300. How fast was the car going wh~er applied the brakes? (This car was not equipped with anti-lock brakes.)