Calculating Total Sound Intensity and Combined Sound Level: Ice Show Example"

[RedPhoenix]

Homework Statement

A family ice show is held at an enclosed arena. The skaters perform to music with level 80.0 dB. This is too loud for your baby, who yells at 75.0 dB.

(a) What total sound intensity engulfs you?
(b) What is the combined sound level?

Homework Equations

dB = 10log(I/1E-12)

The Attempt at a Solution

I am trying to convert back, but I have never been great with logs, and I cannot figure out how to get I.

80=10log(I/1E-12)
75=10log(I/1E-12)

EDIT - it just clicked - anti-derivatives
A)
75db = 10^7.5/1E12 = I(b)
80db = 10^8/1E12 = I(m)
add them for total = 1.316E-4

B)
10log(1.316E-4/1E-12)
81.19dB

 

[Anden]

A hint: Use the fact that 10^log x = x