A motorbike's exhaust pipe emits sound with a frequency of 120 Hz
PHYSICS · Single correct · CBSE · Physics · Waves · A Level
Problem
A motorbike's exhaust pipe emits sound with a frequency of 120 Hz. The motorbike drives directly away from a stationary observer at a speed of 15 ms−1. Which of the following is the best estimate of the frequency of the sound waves from the exhaust pipe detected by the observer? The speed of sound in air is 330 ms−1.
(1) 105 Hz
(2) 110 Hz
(3) 115 Hz
(4) 120 Hz