Two speakers are driven by the same oscillator of frequency 200 Hz. They are located on a vertical pole a distance of 4.00 m from each other. A man walks toward one of the speakers in a direction perpendicular to the pole as shown in Figure 1.
a) How many times will he hear a minimum in sound intensity, and
b) How far is he from the wall at these moments ?
Take the speed of sound to be 330 m/s and ignore any sound reflections coming off the floor.