A wire of length l₀and cross sectional area A supports a hanging weight W

a) Show that the wire behaves like a spring of force constant AY/l₀

Y is the Young's modulus

b) What would the force constant be for a 75.0 centimeter steel wire of diameter 1.29 mm?

Young's modules for steel is 20x10¹⁰ Pascal

Please note, it is for a steel wire not a copper wire

c) What would W have to be to stretch the steel wire in part (b) by 1.25mm?