A handclap on stage in an amphitheater sends out sound waves that scatter from terraces of width w = 0.75 m (Figure). The sound returns to the stage as a periodic series of pulses, one from each terrace; the parade of pulses sounds like a played note.

(a) Assuming that all the rays in Figure are horizontal, find the frequency at which the pulses return (that is, the frequency of the perceived note).

(b) If the width w of the terraces were smaller, would the frequency be higher or lower?