# Homework Help: Sound intensity level of a jet

1. May 18, 2010

### phytitan

1. The problem statement, all variables and given/known data

A jet travelling overhead at an altitude of 5000 feet produces a sound intensity level of 80 dB. What would the figure be for an eight of 1000 feet?

2. Relevant equations

3. The attempt at a solution

2. May 18, 2010

### CanIExplore

If you know the intensity of the sound wave at a certain distance from the source, then you can find the power of the source. Do you remember the equation that relates the power to intensity? This is a good place to start.

Last edited: May 19, 2010
3. May 19, 2010

### phytitan

I have the intensity of the source and I would calculate the power with the formula P=I*A but I don't have the radius I just have a difference in the two radii. But it's an equation with two unknowns the actual radius and the power.

r1=x at 5000 feet altitude
r2=x + 4000 at 1000 feet altitude

how can I calculate the intensity at 1000 feet?

4. May 19, 2010

### CanIExplore

So we have the formula for power, P=IA. What is A in this formula? And when you say radius, with respect to what origin are you referring to? Radius is the distance from where to where?