Consider the rotation of a rod of mass `m` and length `I` from position `AB` to `AB'`. Which of the following statements are correct?

Options

A. Weight of the rod is lowered by `l//2`
B. Loss of gravitational potential energy is `1//2mgl`
C. Angular velocity is `sqrt(3g//l)`
D. Rotational kinetic eneryg is `(ml^(2)omega^(2))/6`

Answer

A, B, C, D

Explanation

Equating loss of gravitational potential energy with the gain of rotational kinetic energy, we get
`1/2Iomega^(2)=1/2mgl`
`1/2xx(ml^(2))/3xxomega=1/2mgl`
`omega=sqrt((3g)/l)`
Rotational kinetic energy `=1/2 (ml^2)/3omega^(2)=(ml^(2)omega^(2))/6`