J(x') d^3 x' 	
	A = 1/c integral[______________]
			    |x-x'|   

        DEL . A = 0  .

Problem 2. Work Numerical Problem 5.05, posting your results on the web. Since this is a test and everyone is working independently, you may want to make a page called prob2.html, link it into your Jackson page, but set its permissions so that only you can look at it (as a local file, not over the network). You do this as follows:

	chmod 700 prob2.html

	chmod 750 prob2.html

Problem 3. (a) Write down Maxwell's equations in their differential form, as appropriate to a region of space with source distributions s_free and J_free of free charge and free-charge current present, but no bound charges.

(b) Using these equations, carry out a calculation similar to that done in the book (pp. 236-237) to find the form of the Poynting vector and the electromagnetic field energy density. To get full credit you must explain all your assumptions and justify all steps in the calculation, and interpret the results in a clear, concise and complete manner.

(c) Consider a wire in the form of a long cylinder of cross-sectional area A and length L, connected to a battery with ideal (resistance-less) wires, as shown in figure 1. The wire consists of a material of resistivity r. The voltage V of the battery causes a constant current I to flow through the wire. Assuming the wire to be long enough to neglect end effects, discuss conservation of energy for this wire, including all of the effects involved in part (b) above.