Question

A steel wire of length 4.7 m and cross-sectional area 3.0 × 10-5 m2 stretches by the same amount as a copper wire of length 3.5 m and cross-sectional area of 4.0 × 10–5 m2 under a given load. What is the ratio of the Young’s modulus of steel to that of copper Question 9.1 machenical properties of the solid

Answer 1

The ratio of Young's modulus of steel to that of copper is 1.79:1


Refer to the attachment .
I hope it will help you.

Answer 2

Young's modulus for steel wire 

Y1 = (F1/A1) x (L1/ΔL1) 

= F1 x 4.7 / 3.0 x 10⁻⁵ x ΔL ----(1) 

Young's modulus for copper 

Y2 = (F2/A2) x (L2 /ΔL2) 

     = F x 3.5 / 4 x 10^-5 x ΔL----(2) 

By 1 and 2 

Y1 / Y2 = 4.7 x 4.0 x 10^-5 / 3.0 x 10^-5 x 3.5 = 1.79 : 1