Question

The radius of a silver bar is 30 𝑐𝑚. What force is required to stretch the bar by

12.7% of its length where Young’s modulus is 𝑌 = 7.25 × 1010 𝑁𝑚−2

Answer 1

According to Hooke's law

$F=EA\cdot\frac{\Delta l}{l}=E\cdot\pi r^2\cdot\frac{0.127l_0}{l_0}=0.127\cdot E\cdot\pi r^2=$

$=0.127\cdot7.25\cdot10^{10}\cdot 3.14\cdot0.3^2=2.6\cdot10^9\ (N)$ . Answer