Question

A source emits a sound and is represented by the red dot in this map. Four people are located around the source, and the circles represent the sound wave.

An illustrations with circles spreading out from a point. On the left the spacing is very close together and on the right the spacing is farther apart. There is an A farthest left and a D farthest right. Just to the right of the dot is C and bove that B.
As the source moves west, which person hears the highest pitch?

person A
person B
person C
person D

Answer 1

Person A.

Because the source is moving west, the wavefronts are compressed on the west side (shorter wavelength → higher frequency) and stretched on the east side. A, being west of the source, hears the highest pitch.