Final answer:
True. Young's modulus is used to determine the stiffness of a material, with a higher modulus indicating a stiffer material. It is calculated as the ratio of stress to strain within the material's elastic limits.
Step-by-step explanation:
True: The stiffness of a material is indeed determined using Young's modulus. In physics, Young's modulus is a measure of the elasticity of a material and is defined as the ratio of the stress applied to a body or substance to the corresponding strain (a measure of deformation) within the elastic limits. This modulus is denoted by the symbol Y, and materials with a high Young's modulus are considered to be stiff because they deform less when subjected to stress.
The stiffness of different materials can differ under tension and compression, and for certain materials, like bone, the Young's modulus for tension and compression can be different. These values are sometimes averaged for practical reasons. Formulaically, Young's modulus (Y) is calculated using the equation Y = (F/A) / (ΔL/Lo), where F is the force applied, A is the cross-sectional area, ΔL is the change in length, and Lo is the original length.