A wire fixed at the upper end stretches by length l by applying a force F. The work done in stretching is

Work done is defined as the energy transferred when a force acts on an object causing it to move. It is calculated as the product of force and displacement in the direction of the force. The unit of work is joule and it is a scalar quantity representing energy transfer.

Class 11 Physics Chapter 8 covers mechanical properties of solids focusing on fundamental concepts such as stress strain and elasticity. It explains how materials deform under applied forces and the mechanisms that allow them to return to their original shapes. Key topics include Hooke’s law different types of stress and practical applications in engineering and construction.