A C-130 Hercules is traveling toward a cliff at the speed of 150 m/s. Its engines emit a tone at frequency f0. We consider that the speed of sound is 340 m/s. What frequency is received by a pilot after reflection from the cliff?
A person standing near a railway track hears the whistle of an approaching train as having a frequency of 1600 Hz. The train’s velocity is 40 m/s.
What is the true frequency of the sound emitted by the whistle?
Often we see a flash of lightning, but do not hear the thunder. As a rule, thunder has a short range of detection — usually less than 25 km (15 miles). Why?