Young’s modulus

Definition

Young's modulus, also known as the elastic modulus, is a measure of the stiffness of a solid material. It quantifies the relationship between tensile stress and strain in a material.

5 Must Know Facts For Your Next Test

1. Young's modulus is denoted by the symbol $E$ and has units of Pascals (Pa).
2. It is defined as $E = \frac{\sigma}{\epsilon}$, where $\sigma$ is the tensile stress and $\epsilon$ is the strain.
3. High values of Young's modulus indicate that the material is very stiff.
4. Young's modulus can be experimentally determined by plotting stress vs. strain and finding the slope in the linear region.
5. It applies only to materials that exhibit linear elasticity up to their yield point.

Review Questions

• What does Young's modulus measure in a material?
• How is Young’s modulus calculated using stress and strain?
• Why might engineers prefer materials with high Young’s modulus for certain applications?

Related terms

Stress:

Stress is the force per unit area on a material, typically measured in Pascals (Pa).

Strain:

Strain is the deformation or displacement per unit length caused by applied stress.

Shear Modulus:

Shear modulus, denoted by $G$, measures a material's response to shear stress and strain.