Question

The Doppler effect indicates that the frequency of energy (sound or light) waves when an object is approaching and when an object is moving away.

Answer 1

Increase

Step-by-step explanation:

Answer 2

Step-by-step explanation:

According to Doppler effect:

1) When the source of the frequency is approaching, The apparent frequency heard by the observer will be more than that of the actual frequency.

`f'=(v)/(v -v_s)* f`

2) When the source of the frequency is moving away, The apparent frequency heard by the observer will be less than that of the actual frequency.

`f'=(v)/(v+v_s)`

f = Real frequency of the source

f' = apparent frequency heard by the observer

v = velocity of the sound

`v_s` = velocity of the source