Practice question
Question
A copper block of dimensions 0.5 m × 0.3 m × 0.2 m is subjected to a shearing force of 7 × 104 N on its top face. If the shear modulus of copper is 4.2 × 1010 N/m2, what is the shear strain?
Explanation
Shear modulus: G = (Shear stress) / (Shear strain). Shear stress: Shear stress = F / A, A = 0.5 × 0.3 = 0.15 m2. Shear stress = (7 × 104) / 0.15 = 4.67 × 105 N/m2. Shear strain: Shear strain = Shear stress / G = (4.67 × 105) / (4.2 × 1010) ≈ 1.11 × 10-5.