Question

A steel bar of 500mm length is under tensile stress of 100 n/mm2 . If the modulus of elasticity is 2x1011 n/m2 , then the total elongation of the bar will be

Answer 1

Hope this helps.........

Answer 2

We know that, Modulus of elasticity, Y= Stress/ Strain----- (1)

Given, stress= 100 N/mm²

 Strain= Δl/l, where Δl is change in length which is asked to find.

Young's modulus Y= 2×10¹¹N/m²= 2×10⁵ N/mm²

So, from equation (1),

Y= stress/(Δl/l)

Δl= (l×stress)/Y

  = (l×100)/(2×10⁵)

  =(500×100)/ 2×10⁵

   = 0.25 mm