Question text
23 A car travelling in a straight line at a speed of 30 m s–1 passes near a stationary observer while sounding its horn. The frequency of sound emitted by the horn is 400 Hz. The speed of sound in air is 336 m s–1. What is the change in the frequency of the sound heard by the observer as the car passes? A 39 Hz B 66 Hz C 72 Hz D 78 Hz
23 A car travelling in a straight line at a speed of 30 m s–1 passes near a stationary observer while
sounding its horn. The frequency of sound emitted by the horn is 400 Hz.
The speed of sound in air is 336 m s–1.
What is the change in the frequency of the sound heard by the observer as the car passes?
A 39 Hz B 66 Hz C 72 Hz D 78 Hz
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