Question
Physics Question on Stress and Strain
The energy stored per unit volume in copper wire, which produces longitudinal strain of 0.1% is (Y=1.1×103Nm−2)
A
11×103Jm−3
B
5.5×103Jm−3
C
5.5×104Jm−3
D
11×104Jm−3
Answer
5.5×104Jm−3
Explanation
Solution
Elastic potential energy per unit volume of the wire u=21×stress×strain =21×(Young′smodulus×strain)×strain =21×(Y)×(strain)2 ∴ u=21×1.1×1011×(1000.1)2 =5.5×104Jm−3