Question

Give reason
Loudness of sound decrease as one moves away from the source of sound.​

Answer 1

As sound waves travel farther from their source, the more spread out their energy becomes. ... The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source.

Answer 2

f' = V+Vo V+Vsfwhere f' is the new frequency heard f is the original frequencyV is speed of soundVo is speed of obseverVs is speed of sourceSo,f' = V+Vo Vff' = V+V/5 Vff' = 6f/5% increase = 1/5*100 = 20 %