What does Young's Modulus of Elasticity (E) express in materials?

Young's Modulus of Elasticity (E) is a fundamental property of materials that quantifies their stiffness or rigidity. It expresses the linear relationship between stress (force per unit area) and strain (deformation relative to the original length) within the elastic limit of the material. This relationship is essential in understanding how materials will behave when subjected to forces.

When a material is stretched or compressed, Young's Modulus helps predict how much it will deform under a given load. A high Young's Modulus indicates that the material is stiff and does not stretch easily, while a low modulus suggests that the material is more flexible. Thus, this ratio is a crucial parameter used in engineering to ensure that structures can withstand the loads they will experience without undergoing excessive deformation.

The other options refer to different aspects of material behavior but do not accurately describe Young's Modulus. For instance, the relationship between weight and volume pertains more to density, while maximum elongation before failure relates to ultimate tensile strength, and total energy absorbed concerns toughness.