6.1.6—The Young modulus of a metal in the form of a wire
- Syllabus
- 9702–2028–2029
- Objective
- 6.1.6
- Level
- AS
Young modulus of a wire can be found from force, extension, length and area
For a uniform wire in the linear region, E=(F/A)/(x/L)=FL/(Ax).
Measure original length L, extension x, force F and cross-sectional area A; use diameter carefully because A=πd²/4.
A longer wire extends more under the same load, but Young modulus remains a material property when dimensions are accounted for.
Do not compare raw extension to judge material stiffness without allowing for length, area and force.
ConceptA-Level CAIE Physics AS