1. Deduce a set of boundary-layer differential equations (continuity, momentum, energy) for steady flow of a constant-property fluid without body forces, and with negligible viscous dissipation, in a coordinate system suitable for analysis of the boundary layer on the surface of a rotating disk.

2. Starting with the general viscous energy equation, show by a succession of steps how and why it reduces to the classic heat-conduction equation for a solid, and finally to the Laplace equation.