Answer:
Spring constant = YA / L
Explanation:
Let F be the force being applied on cross sectional area A of metal bar due to which an extension of ΔL is obtained in the wire of length L then
stress = F / A
strain = ΔL /L
Young's modulus = ( F / A ) / (ΔL /L)
Y = ( F L / A ΔL )
( F / ΔL ) = ( YA / L )
Spring constant = ( F / ΔL )
Spring constant = YA / L
When you touch a doorknob (or something else made of metal), which has a positive charge with few electrons, the extra electrons want to jump from you to the knob. That tiny shock you feel is a result of the quick movement of these electrons.