A steel rod has a radius of 20   mm and a length of 2 . 0   m . A force of 62 . 8   kN stretches it along its length. Young's modulus of steel is 2 . 0 × 10 11 N   m - 2 . The longitudinal strain produced in the wire is _ _ _ _ _ _ _ _ _ × 10 - 5 .

Step-by-step solution

Young's modulus is given as Y = Stress Strain = F A ∆ L L The given data is Stress = 62 . 8   kN r = 20 × 10 - 3   m Y = 2 × 10 11   N   m - 2 Thus, Strain = F A × Y ⇒ ∆ L L = 62 . 8 × 10 3   N π × 20 × 10 - 3   m 2 × 2 × 10 11   N   m - 2 = 25 × 10 - 5   N