Two train whistles, A and B , each have a frequency of 396 Hz . A…

Two train whistles, A and B , each have a
frequency of 396 Hz . A is stationary and B is
moving toward the right (away from A ) at a speed of 35.0
m/s . A listener is between the two whistles and is moving toward
the right with a speed of 15.0 m/s . (See (Figure 1) .)

Part A
What is the frequency from A as heard by the
listener?
Express your answer in hertz
Part B
What is the frequency from B as heard by the
listener?
Express your answer in hertz
Part C
What is the beat frequency detected by the listener?
Express your answer in hertz
UL 15.0 m/s vB 35.0 m/s