LaPlace's Equation in Sphereical Coordinates

[TwilightTulip]

Homework Statement

I want to cook a 4" meatball. The meatball is being stored in the fridge at 35 degrees F. The meatball will go into a convection oven at 350 degrees F (surface is maintained at precisely 350 for the duration of cooking). I want to cook the meatball to 130 degrees F (in the center).

Homework Equations

LaPlacian = 0?

The Attempt at a Solution

How do I set it up and start the separation of variables?

 

[TwilightTulip]

Any ideas?