Question

Question) A steel wire of length 5.0 m and cross - section $3.0\times {10}^{-5}{m}^2$stretches by the same amount as a copper wire of length 3.0 m and cross - section $4.0\times {10}^{-5}{m}^2$ under a given load. What is the ratio of Young' s modulus of steel to that of copper?

Answer 1

Dear Student ,


$$\begin{gathered} l=5m,A=3*{10}^{-5}{m}^2 \\ {Y}_{steel}=\frac{5F}{3*{10}^{-5}*∆l} \\ {Y}_{Cu}=\frac{3F}{4*{10}^{-5}*∆l} \\ \frac{Y_{steel}}{Y_{Cu}}=\frac{5*4*{10}^{-5}}{3*3*{10}^{-5}}=\frac{20}{9} \\ Regards \end{gathered}$$