To find the extension of a brass rod. To solve this, we use the formula for Young's Modulus, which relates stress and strain.

The problem asks to find the extension of a brass rod. To solve this, we use the formula for Young's Modulus, which relates stress and strain.

The formula for Young's Modulus ($Y$) is:

$$Y = \frac{\text{Stress}}{\text{Strain}} = \frac{F/A}{\Delta L/L}$$

where:

• $F$ is the applied force
• $A$ is the cross-sectional area
• $\Delta L$ is the extension (change in length)
• $L$ is the original length

We need to find $\Delta L$. Rearranging the formula gives:

$$\Delta L = \frac{F \cdot L}{A \cdot Y}$$