3. an underground copper pipe is used to transport oil under a factory. it is very important that this pipe does not oxidize, so engineers use impressed current cathodic protection. a. would zinc be an appropriate metal to use for cathodic protection? why or why not? (4 points) b. engineers attach a sacrificial anode to the copper pipe. to use impressed current cathodic protection, they must attach a battery between the cathode and anode. which material should the positive side of the battery be attached to? explain how you know. (4 points)