Two particle of mass m each are fixed to a massless rod of length 2l . The rod is hinged at one end about a smooth hinge and it performs oscillations of small angle in vertical plane. The length of the equivalent simple pendulum is:

Options

A. `(3l)/2`
B. `(10l)/3`
C. `(5l)/3`
D. None of these

Explanation

`T=2pisqrt(I/(mgl)), I=ml^(2)+m(2l)^(2)=5ml^(2)`
`=2pisqrt((5ml^(2))/(2mg (3l)/2))=2pisqrt((5l)/(3g))`
`:. L_(eq)=(5l)/3`