Two cars are stuck in a traffic jam and each sounds its horn at a frequency of 531 Hz. A bicyclist between the two cars, r = 4.36 m from each horn (see the figure below), is disturbed to find she is at a point of constructive interference. How far backward (in m) must she move to reach the nearest point of destructive interference? Take the speed of sound to be v = 343 m/s.