In order to protect underground pipelines and storage tanks made of iron, the iron is made the cathode of a voltaic cell through a process called anodizationcathodic

The answer would be that the process to protect the underground pipelines and storage tanks is cathodic protection.

i think it would be 5

initial speed when it is dropped is 150 ft/s

now at the same moment the acceleration due to gravity is perpendicular to its velocity

so as we know that

now we have centripetal acceleration a = 32 ft/s^2 as its perpendicular to velocity

while tangential acceleration at the same moment will be zero

so

now radius of curvature is given as

so the radius of curvature just after it is dropped is 703.125 ft