Question

A railroad locomotive is at rest with its whistle shrieking and then it starts moving toward you.  Describe what happens to the frequency and wavelength of the sound that hits your ear when:A) It is approaching you.B) It pulls away from you.What happens to the amplitude in both of these scenarios?

Answer 1

a) Frequency increases , the time between waves decreases , wavelenghts decrease

b) Frequency decreases , wavelenght increases.

The doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. AS the source approaches the listener , the sound waves get closer together, increasing their frequency and decreasing their wavelenghts.

Amplitude remains the same.