Question

A steel wire of length 20cm is stretched to increase the length by 0.2cm find the lateral strain in the wire if Poisson's ratio is 0.19

Answer 1

Poisson's Ration (σ) = -ΔD/D / Δl/l

σ = 0.19 ( Given )

l = 20 cm = 20 x 10 ⁻² m

Δl = 0.2 cm = 0.2 x 10 ⁻² m

ΔD/D = - σ x Δ l/l

ΔD/D = - 0.19 x 0.2 x 10⁻² / 20 x 10⁻²

ΔD/D = - 0.19 x 0.2 /20

Lateral strain

ΔD/D = 0.038/20

ΔD/D = 0.0019 = 1.9 x 10⁻³