Question

A metal bar 2.5 m long extends by 0.05 mm when a tensile load is applied to it. Determine 

(a) the strain, 

(b) the percentage strain.

Answer 1

(a) Strain \(\varepsilon\) = \(\cfrac{extension}{original\, lengh}\) = \(\cfrac{0.05\,mm}{2.5\times10^3\,mm}\)

= \(\cfrac{0.05}{2500}\) = 0.00002

(b) Percentage strain = 0.00002  100 = 0.002%