A structural steel rod has a radius of 10 mm and length of 1.0m. A 100 kN force stretches it along its length Young's modulus of structural steel is `2xx 10^(11) Nm^(-2)`
Elastic energy density of stretched todis

Options

A. `1.26xx10^(5) Jm^(-3)`
B. `2.53xx10^(5) Jm^(-3)`
C. `3.9xx10^(5) Jm^(-3)`
D. `5.06xx10^(5) Jm^(-3)`

Answer

B

Explanation

Elastic energy density `= (1)/(2) xx "stress " xx "strain"`
`(1)/(2) xx (10^(5))/(pi xx 10^(-4)) xx 1.59 xx 10^(-3)= = 2.53 xx 10^(5) J//m^(3)`