Doppler Effect: Sound Level at 40m from Source of 20dB

[jan2905]

At a distance of 20m from a source of sound, the sound level is 40dB. If the observer backs up to a distance of 40m from the source, what will the sound level be?



Basically, I said that the sound level halved = 20dB. Correct?

 

[Prosthetic Head]

not necessarily, do you have any equations with which to calculate this?

 

[jan2905]

No. This is why I am assuming that it just halves haha.