How does power relate to intensity?

[beanryu]

In this problem you will use the decibel scale to analyze a small firecracker that emits 1200 W of peak power.

How does I(the intensity) relate to 1200 peak power?

THANKYOU!

 

[Tide]

Intensity is power per unit area.

 

[beanryu]

Oh, I think I figured it out, the area is the area of the sphere, not a circle!
Isn't it right?

 

[Pengwuino]

The surface area you mean?

 

[beanryu]

P/A where A is the area of a sphere! isn't it?