Worksheet $12$ new $-$ Understanding Waves

Problem $3-$ Noisy Trees

You are standing $100$ m from a tree pruning crew that is grinding up trees $($loud$!)$ and you hear an intensity of $4\mathrm{.}5{10}^{-6}\frac{(W)}{m^2}.$ What is the sound level that someone $10$ m from the tree grinding would be hearing?

$=$

Problem $4-$ Turn it Up$!$

You are playing your stereo, and the sound level is unknown. You turn the volume up$,$ and the sound level increases by $20$ dB $.$ Show mathematically that the intensity of sound you are hearing went up by times $100$ when you increased the volume by $20$ dB $.$

Problem $5-$ Rocking Out

Two large speakers are placed on the left and right corners of a stage, exactly $10$ m apart from each other. You are standing $5$ m from the stage, in front of the left speaker.

$($a$)$ How far away from the right speaker are you standing?

$d_R=$

$($b$)$ What are the three lowest frequencies of sound are interfering destructively where you are standing?

Destructive frequencies $=$

$2$