Mechanical Properties of Solids

The length of a metal wire is L₁ when the tension is T₁ and L₂ when the tension is T₂. The unstretched length of wire is

• $\frac{{\mathrm{L}}_1 + {\mathrm{L}}_2}{2}$

• $\sqrt{{\mathrm{L}}_1{\mathrm{L}}_2}$

• $\frac{{\mathrm{T}}_2{\mathrm{L}}_1 - {\mathrm{T}}_1{\mathrm{L}}_2}{{\mathrm{T}}_2 - {\mathrm{T}}_1}$

• $\frac{{\mathrm{T}}_2{\mathrm{L}}_1 + {\mathrm{T}}_1{\mathrm{L}}_2}{{\mathrm{T}}_2 + {\mathrm{T}}_1}$