Cold working of iron leads to increase in dislocation density from 10¹⁰ to 10¹⁵ m⁻². The associated stored energy (in MJ⋅m⁻³, rounded off to one decimal place) is _______.
Given: Shear modulus of iron = 82 GPa; Burger's vector, b⃗ = a₀/2. a₀ = 0.2856 nm.