A plane flies toward a stationary siren at 1/4 the speed of sound.Then the plane stands still on the ground and the siren is driven toward it at 1/4 the speed of sound.In both cases,a person sitting in the plane will hear the same frequency of sound from the siren.

Question

Quizplus · Accepted Answer

When the plane is moving towards the siren, the frequency heard by someone in the plane increases due to the Doppler effect. When the plane is stationary and the siren moves towards it, the frequency also increases, but the amount of increase is different in each scenario due to the relative motion between the source and the observer.

A Plane Flies Toward a Stationary Siren at 1/4 the Speed