A caterpillar of length 4.0 cm crawls in the direction of electron drift along a 5.2-mm-diameter bare copper wire that carries a uniform current of 12 A.

(a) What is the potential difference between the two ends of the caterpillar?

(b) Is its tail positive or negative relative to its head?

(c) How much time does the caterpillar take to crawl 1.0 cm if it crawls at the drift speed of the electrons in the wire? (The number of charge carriers per unit volume is 8.49 x 1028 m-3.)