Galvanisation is a process is which __________ is coated as a layer on iron.

Opsonization is a process in which pathogens are coated with substance called

A spherical iron ball 10cm in radius is coated with a layer of ice of uniform thickness that melts at a rate of 50c m^3//m in . When the thickness of ice is 5cm, then find the rate at which the thickness of ice decreases.