In biomechanics, which term is defined as change in length divided by original length?

In biomechanics, which term is defined as change in length divided by original length?

• A. Stress
• B. Poisson's ratio
• C. Change in length divided by original length
• D. Young's modulus

Answer: (C)

Strain is the measure of deformation that matches this definition: change in length divided by the original length. It’s a dimensionless quantity, often written as ε = ΔL / L0, and it tells you how much a material stretches or shortens under load. In biomechanics this lets you quantify how tissues deform, whether a tendon lengthens slightly under a given force or a bone experiences more significant extension. Stress, in contrast, is the internal force per area that drives deformation. Poisson’s ratio relates transverse and axial strains for a material, describing how much it contracts laterally when stretched. Young’s modulus links stress to strain in the elastic region to describe stiffness. So the exact phrase provided describes strain.

Strain is the measure of deformation that matches this definition: change in length divided by the original length. It’s a dimensionless quantity, often written as ε = ΔL / L0, and it tells you how much a material stretches or shortens under load. In biomechanics this lets you quantify how tissues deform, whether a tendon lengthens slightly under a given force or a bone experiences more significant extension.

Stress, in contrast, is the internal force per area that drives deformation. Poisson’s ratio relates transverse and axial strains for a material, describing how much it contracts laterally when stretched. Young’s modulus links stress to strain in the elastic region to describe stiffness. So the exact phrase provided describes strain.