A rod with rectangular cross section oscillates about a horizontal axis passing through one of its ends and it behaves like a seconds pendulum, its length will be

Options

A. 1.5 m
B. 1 m
C. 3 m
D. 2 m

Answer

A

Explanation

`T = 2 pi sqrt((I)/(mgd))`
`2 = 2pi sqrt(((ml^(2))/(12) + m ((l)/(2))^(2))/(mg((l)/(2))))`
`l = (3g)/(2pi^(2)) = 1.5 m`