Question

Wire 10cm long of area of cross section 1.28cm^2 elongates by 1.4cm when 4.5kg is suspended from it. Find the stress and strain and young's modulus

Answer 1

Explanation:

Stress = force / area

σ = F / A

σ = (4.5 kg × 9.8 m/s²) / (1.28 cm² × (1 m / 100 cm)²)

σ = 344,531 Pa

σ = 345 kPa

Strain = elongation / initial length

ε = ΔL / L₀

ε = 1.4 cm / 10 cm

ε = 0.14

Young's modulus = stress / strain

E = σ / ε

E = 345 kPa / 0.14

E = 2460 kPa