Question: how do I plot polar and rectangular functions?

I have two functions that I need to combine to create a plot

Functions as follows:

x^2+y^2=10000,  radius of 100

z=e^(-r)  r=0..100

it comes from the problem of a sprinkler distributing water in a pattern with radius 100 at a depth of e^(-r) feet per hour at a distance r from the sprinkler

I need to somehow plot the 3d graph of z=e^(-r) r=0..100 with the bounds of radius 100 and z greater then 0.

Any help would be great, if it helps the volume from the integral=2pi.

Thank You!

Please Wait...