Question

How do you find the Young's modulus from a load extension graph?

Answer 1

Young’s Modulus:

1. According to many experimental findings and results, the strain produced in a given material has the same shape, regardless of whether the strain is ductile or compressive.
2. The definition or expression of Young's modulus, indicated by the symbol "$Y$", is the relationship between longitudinal stress and tensile or compressive stress.
3. $Y=\sigma \epsilon$
4. The unit of Young's modulus is the same as the unit of stress, which is $N/m^2$, or Pascal because stress is a dimensionless quantity $\left(Pa\right)$.
5. The Young’s modulus of any material can be acquired or calculated by a stress-strain graph which can be derived from load extension graphs.
6. The slope of this graph will be the answer. The slope of this load extension graph is the key to determining Young’s modulus, the only condition is that the material has to obey Hooke's law.

Young's modulus diagram: