PDE: LaPlace's Equation using spherical coordinates (make use of symmetry to make theta and phi dependence drop out)
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).