The length, s, (in feet) of the skid mark left by an automobile traveling at r miles per hour can be approximated by the relation r = 2Square root of...

The length, s, (in feet) of the skid mark left by an automobile traveling at r miles per hour can be approximated by the relation r = 2Square root of 5s. At the scene of an accident, police measured a skid mark of 361 feet. About how many miles per hour was the car traveling when the brakes were applied?