A source of sound moves at a constant speed towards a stationary observer. The frequency of
the observed sound wave differs from the frequency of the emitted sound wave.
The frequency of the observed sound wave is
A higher because the speed of the observed wave is higher.
B higher because the wavefronts are compressed.
C lower because the speed of the observed wave is lower.
D lower because the wavefronts are spread out.
B higher because the wavefronts are compressed 1
Incorrect answers:
A the speed of the wave would not change due to relative motion between the
source and the observer
C the frequency would only be lower if the source was moving away from
the observer
D the frequency would only be lower if the source was moving away from
the observer