A 500-Hz whistle is moved toward a listener at a speed of 10.0 m/s.At the same time,the listener moves at a speed of 20.0 m/s in a direction toward the whistle.What is the apparent frequency heard by the listener? (The speed of sound is 340 m/s. )
A) 473 Hz
B) 485 Hz
C) 533 Hz
D) 545 Hz

Question

Quizplus · Accepted Answer

The apparent frequency can be calculated using the Doppler effect formula: f' = f * (v + v_l) / (v - v_s), where f is the source frequency (500 Hz), v is the speed of sound (340 m/s), v_l is the speed of the listener (20 m/s), and v_s is the speed of the source (10 m/s). Plugging in the values, f' = 500 * (340 + 20) / (340 - 10) = 545 Hz.

A 500-Hz Whistle Is Moved Toward a Listener at a Speed