A sound source approaches a stationary observer. The frequency heard by the observer is
A. higher than the source.
B. lower than the source.
C. the same as that of the source.
D. equal to zero.
Answer:A
A sound source approaches a stationary observer. The frequency heard by the observer is
A. higher than the source. B. lower than the source. C. the same as that of the source. D. equal to zero.