Answer:
k = Y*A/L
Step-by-step explanation:
We can apply the Law of Hooke in order to explain the problem.
If we define k = F / ΔL and the Y = S / δ
Where S is the uniaxial stress: S = F / A (i)
and δ is the strain: δ = ΔL / L (ii)
ΔL is the change in length
we can combine the equations i and ii as follows
Y = (F / A) / (ΔL / L) = (F * L) / (A * ΔL) (iii)
if k = F / ΔL the equation iii results
Y = k * (L / A) ⇒ k = Y*(A / L)