Question

A copper metal cube has each side of length $1m$. The bottom edge of the cube is fixed and tangential force $4.2\times {10}^{8}N$ is applied to a top surface. Calculate the lateral displacement of the top surface if modulus of rigidity of copper is $14\times {10}^{10}N/m^2$.

Answer 1

Given, length, $l=1m,F=4.2\times {10}^{8}N,\eta =14\times {10}^{10}N/m^2$
Now, $\because$ $\eta =\frac{F}{A\theta }$
$\Rightarrow 14\times {10}^{10}=\frac{4.2\times {10}^8}{1\times 1\times \theta }$
$\Rightarrow \theta =\frac{4.2\times {10}^8}{14\times {10}^{10}}=0.003m=3\times {10}^{-3}m$