The elastic potential energy of a stretched wire is given by
U=AL2Yl2
U=AY2Ll2
U=12ALlYl
U=12⋅YL2A⋅l
Elastic potential energy of a stretched wire is given by
U=12× Stress × Strain × Volume
=12×Y× Strain × Strain × Volume
=12×Y×lL2×AL
∴ U=AYl22L