A lightning bolt strikes one end of a steel lightning rod, producing a 15,000-A current burst that lasts for 65 µs. The rod is 20 m long and 1.8 cm in diameter and its other end is connected to the ground by 35 m of 8.0-mm-diameter copper wire.
(a) Find the potential difference between the top of the steel rod and the lower end of the copper wire during the current burst.
(b) Find the total energy deposited in the rod and wire by the current burst.