A single jet engine that is 100 feet away from the listener has a noise level of 140dB.

a) Find the sound intensity of the jet engine in watts/cm

b) Suppose two jet engines are 100 feet away from a person, each with the same sound intensity as the jet engine from part (a). What is the combined noise level in decibels? [Hint: the combined sound intensity is the sum of the intensities of the two engines.]

c) Suppose a source has sound intensity * two * sources with sound intensity

d) Using properties of logarithms, write the expression from part (c) as the sum of two logarithms.