HELP PLEASE! Spherical Sound Waves Problem

1. Dec 13, 2005

cmilho10

A jackhammer, operated continuously at a construction site, behaves as a point source of spherical sound waves. A construction supervisor stands 63.5 m due north of this sound source and begins to walk due west. How far does she have to walk in order for the amplitude of the wave function to drop by a factor of 2.10?

Could someone point me in the right direction on solving this please?

2. Dec 13, 2005

wormhole

i hope i right

take origin as place where jackhammer is
$y_0$ is where supervisor at the beggining.
you know that amplidute falls with the distance as $\frac{A_0}{r}$

assume that supervisor walks in positive x direction distance s

3. Dec 13, 2005

cmilho10

ok....but I'm still confused about what to do with these relationships and the numbers given in the problem

4. Dec 13, 2005

wormhole

$$\frac{A_0}{r}=2.1$$
=>$r=\frac{A_0}{2.1}$

finaly

$$y_0^2+x^2=r^2=(\frac{A_0}{2.1})^2$$

Last edited: Dec 13, 2005