A steel rod of length L, density d and cross-sectional area A, is hinged at one end so that it can rotate freely in a vertical plane. The rod is released from a horizontal position. When it becomes vertical, the stress at its midpoint is

Options

A. 13dLg/8
B. 12dLg /8
C. 2dL g/5
D. dLg/2

Answer

1

Explanation

`mg1/2 =1/2xx(ml^(2))/3 omega^(2)`
`omega=sqrt((3g)/L)`
`T-m/(2g)=m/2 omega^(2)xx(3L)/4`
`T=(mg)/2+3/8xx3 mg =(13 mg)/8`