Question

Two parallel and opposite forces each $5000\, N $ are applied tangentially to the upper and lower faces of a cubical metal block of side $25 \,cm$. The angle of shear is (The shear modulus of the metal is $80 \,GPa$.)

• A. $10^{-4}\, rad$
• B. $10^{-5}\, rad$
• C. $10^{-6}\, rad$
• D. $10^{-7}\, rad$

Answer 1

The Correct Option is C

Here, $F= 5000 \,N$ $L=25\, cm$ $=25\times10^{-2}\,m$ $A$ $=\left(25\times10^{-2}m\right)^{2}$ $=625\times10^{-4}m^{2}$ $\eta=80 Gpa$ $=80\times10^{9}pa$ Angle of shear, $\theta$ $=\frac{F}{A\eta}$ $=\frac{5000}{625\times10 ^{-4}\times80\times10^{9}}$ $=10^{-6} \, rad$