The amount of deformation compared to the original size of a body is referred to as what in applied mechanics?

The amount of deformation compared to the original size of a body is referred to as strain in applied mechanics. Strain quantifies how much a material deforms when subjected to an applied load or stress. Specifically, strain is defined as the change in length (deformation) divided by the original length of the material. This dimensionless ratio provides a clear understanding of how significantly a material has altered from its original configuration, which is crucial in evaluating the material's performance under various loads and conditions.

Understanding strain is essential for engineers and power engineers, as it helps in analyzing the behavior of materials in structures and machinery, ensuring safety and functionality. The other terms have specific meanings; stress pertains to the internal forces within a material, set refers to a permanent deformation, and variable relates to something that can change, but these do not describe the relationship of deformation to original size as strain does.