Question

. What is the Doppler effect? What causes it?

Answer 1

So the Doppler Effect is when an object emitting waves moves, it changes the frequency, The waves in front get pushed closer together while the ones behind get more spread out

Answer 2

when the source of a sound wave and the observer of a sound wave are moving with respect to each other, the sound becomes distorted; when the waves are compressed close to each other, the pitch increases, and when the waves are spread out, the pitch decreases

ex: when an ambulance drives past with its siren on, you hear the siren's pitch increase when it gets close and lowers again when the ambulance is farther away