Question

A rubber cube of side $7cm$ has one side fixed while a tangential force equal to $1800N$ is applied to opposite face. Find the shearing strain and the lateral displacement of the strained face [Modulus of rigidity for rubber is $2.4\times {10}^{6}N/m^2$]

Answer 1

$L=5\times {10}^{-2}m$ $\Rightarrow$ $\frac{F}{A}=\eta \frac{x}{L}$
strain $\theta =\frac{F}{A\eta }=\frac{1800}{25\times {10}^{-4}\times 2.4\times {10}^6}=\frac{180}{25\times 24}=\frac{3}{10}=0.3$ radian
$\frac{x}{L}=0.3$ $\Rightarrow$ $x=0.3\times 5\times 5\times {10}^{-2}=1.5\times {10}^{-2}m=1.5cm$