You are sitting at an intersection late at night

You are sitting at an intersection late at night. No one seems to be around and you are about to

enter the intersection when a car rounds a curve and hits his horn seeing you there. You hit your

horn in return as the other car drives through the intersection and past your stopped car. A beat

frequency of 6.0 Hz can be heard. If both of your horns have frequencies of 260 Hz, how fast was

the other car going? include coordinate system, all formulas used, drawing , and all units