400
A car is traveling at 50 miles per hour due south, at a point 1/2 miles north of an intersection. A police car is traveling at 40 miles per hour due westat a point 1/4 miles east of the same intersection. At that instant the radar in the police car measures the rate at which the distance between the two car is changing, what does the radar gun register?
What is 62.6 miles per hour