10 The police department uses a formula to determine the speed at which a car was going when the driver applied the brakes by measuring the distance of the skid marks The equation d 0 0020r r models the distance d in feet traveled after applying the brakes in a car moving r miles per hour r is the speed of the car If the distance the car traveled after applying the brakes equals 42 feet what what was the speed of the car Round your answer to the nearest hundredth miles per hour Answer mph