Young's Modulus (Y = σ/ε = (F × L)/(A × ΔL))
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Y = σ/ε = (F × L)/(A × ΔL)
What each symbol means
| Symbol | What it stands for |
|---|---|
| A | Cross-sectional area (m²) |
| F | Applied force (N) |
| L | Original length (m) |
| Y | Young's modulus (Pa or N m⁻²) |
| ε | Longitudinal strain = ΔL/L (dimensionless) |
| σ | Tensile or compressive stress = F/A (Pa) |
| ΔL | Change in length (m) |
When to use this
Applies to tensile and compressive stress within elastic limit. Same Y whether stress is tensile or compressive. Only relevant for solids (not liquids or gases). Steel Y ≈ 2 × 10¹¹ Pa, Bone Y ≈ 9.4 × 10⁹ Pa.