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

Answer

C

Explanation

Two particle
`T=2pisqrt(1/(mgl)),I=ml^(2)+m(2n^(2)=5mt^(2))`
`=2pisqrt((5ml^(2))/(2mg(3l)/2))=2pisqrt((5l)/(3g))`
`:.L_(40)=(5l)/3`