Tuning Fork Homework: Intensity & dB Level

[anotherperson]

Homework Statement

A tuning for, fork A, is struck and rings with a frequency of 1000Hz, emitting a power of 4x3.14159 x10^-6

a)what is the intensity of the sound, in w/m^2, that would be measured 1.0 from the tuning fork? assume that the tuning fork approximates a point source?

b) what is the intensity level in dB of this sound?

Homework Equations

I=P/A
B=10log10(I/Io) Io=10^-12

The Attempt at a Solution

i have no clue how to work out part a. but i know the solution to part a become the value of I and then you solve for B in part b

 

[MisterX]

The effects of a point source would spread equally in all directions. Assume all the power stays as a sound wave. Imagine sound waves eminating spherically (in all directions equally) from a point at the speed of sound. At the surface of any sphere centered around the point, the sound intensity will be the same. The total power of sound passing through the spherical surface will be equal to the power of the source, since no power was lost.