Question

We want to punch a hole of diameter 2 cm in a metal plate of thickness 8 mm. If shear strength of metal is $500\times {10}^{6}N/m^2$. What Force is required to punch hole?

• A. 5000 N
• B. $2.5\times {10}^5$ N
• C. $\pi \times {10}^5$ N
• D. 8000 N

Answer 1

The correct option is B $2.5\times {10}^5$ N

By stress =$\frac{\text{Force}}{\text{Area}}\Rightarrow =\text{Stress}\times \text{Area}$

$F=5\times 2\pi rt$

$F=500\times {10}^6\times 2\times 3.14\times \frac{1}{100}\times \frac{8}{1000}$

$F=2.5\times {10}^5$ N