A potter forms a piece of clay into a cylinder. As he rolls it, the length, L, of the cylinder increases and the radius, R, decreases. Assume that no clay is lost in the process. Suppose the length of the cylinder is increasing by 0.2 cm per second.

(a) What is the rate at which the volume is changing?

cm3/sec

(b) What is the rate at which the radius is changing when the radius is 3 cm and the length is 5 cm?

im not sure how the to relate the length and radius, help please!