At a distance of 30 m the noise from the engine of an jet has an intensity of 130 dB.

At this level, you will be in pain and your ears will hurt. That's why this intensity is know as the "pain threshold".

How far do you have to be from a jet (total distance), in order for the noise to drop down in intensity to 62.2 dB, a level comparable to that of a spoken conversation?

2 answers

You are after a 67.8 dB reduction, which is a reduction by a factor of 6*10^6 in sound power per area (intensity). You will have to be 2400 times farther away.
Im doing this question right now and I cant understand it! how did you get that value?!