Attempt any THREE :
Derive an expression for strain energy. Hence show that strain energy per unit volume is directly proportional to the square of the stress.

Explanation

To derive an expression for strain energy and show that strain energy per unit volume is directly proportional to the square of the stress, we can follow these steps:

### Step 1: Understand Young's Modulus
Young's modulus (Y) is defined as the ratio of stress (σ) to strain (ε):
\[ Y = \frac{\sigma}{\epsilon} \]
where:
...