Question

The stress in a steel bar is given as 25,0000 kN/m² and length of the bar is 50 m. Calculate the shortening of the bar if E = 2.14 × 10⁸ N/mm²
1. 0.160 mm
2. 0.0584 mm
3. 0.250 mm
4. 0.305 mm
5. 1.202 mm

Answer 1

Correct Answer - Option 2 : 0.0584 mm

Explanation

 Shortening of bar is given by = ϵL × L

 we know , strain ϵ = σ/E

Given,

Length of bar = 50 m = 50000 mm

stress σ = 250000 kN/m² = 250 N/mm², ( 1 m² = 10⁶ mm²)

 E = 2.14 × 10 ⁸ N/mm²

 Shortening of bar = (250 / 2.14 × 10⁸) × 50000

 = 0.0584 mm