I think that for energy of a spring I should use (1/2)(k)(x^2) and (1/2)(m)(v^2) but i'm not sure what to do with the equations to solve the problem.

A cylindrically shaped piece of collagen is being stretched by a force that increases from 0 to 3.0 x 10^-2 N. The length and radius of the collagen are respectively 2.5 and 0.091 cm and Young’s molulus is 3.1 x 10^6 N/m^2.
(A) If the stretching obeys Hooke’s Law, what is the spring constant for collagen?
(B) How much work is done by the variable force that stretches the collagen?

force= Y (deltaL/L)area

so, if hookes law is F=k deltax
then force/deltax= k=Y*area/length

calculate k.

work done? 1/2 k x^2