Question

A 200 kg load is hung on a wire having a length of 4 m, cross-sectional area 1.2 x10-4 m2 , and Young‘s modulus 8 x 1010 N/m2 . What is its increase in length?

Answer 1

$m=200 \; kg \\ L=4 \; m \\ Y = 8 \times 10^{10} \; N/m^2 \\ A = 1.2 \times 10^{-4} \; m^2 \\ Y = \frac{f/A}{ΔL/L} \\ ΔL = \frac{200 \times 9.8 \times 4}{1.2 \times 10^{-4} \times 8 \times 10^{10}} \\ ΔL = 0.816 \times 10^{-3} \; m$