2.38 - Repulsion between hemispheres of a charged metal sphere
2.39 - Capacitance per unit length of a coaxial cable
2.40 - Work done moving parallel capacitor plates
3.1 - Find the average potential over a spherical surface

Examples class week 5

2.37 - Pressure on parallel capacitor plates
2.50 - Conceptual problem with E=(ax,0,0)
3.2 - Earnshaw's theorem for electrostatics

Bonus questions

B4.1 - Show that solving Laplace's equation is equivalent to minimizing the total electrostatic energy subject to the boundary conditions.  Also, show that the potential V(r) can never have a maximum or a minimum in free space (proving Earnshaw's theorem).