A thin bar of mass `m` and length `l` is free to rotate about a fixed horizontal axis through a point at its end.The bar is brought to a horizontal position. `(theta = 90^(@))` and then released. The angular velocity when it reaches the lowest point isA. directly proportional to its length and inversely proportional to its massB. independent of mass and inversely proportional to the square root of its lengthC. dependent only upon the acceleration due to gravity and the mass of the barD. directly proportional to its length and inversely proportional to its length and inversely proportional to the acceleration due to gravity.

A thin bar of mass `m` and length `l` is free to rotate about a fixed

1.	A thin bar of mass `m` and length `l` is free to rotate about a fixed horizontal axis through a point at its end.The bar is brought to a horizontal position. `(theta = 90^(@))` and then released. The angular velocity when it reaches the lowest point isA. directly proportional to its length and inversely proportional to its massB. independent of mass and inversely proportional to the square root of its lengthC. dependent only upon the acceleration due to gravity and the mass of the barD. directly proportional to its length and inversely proportional to its length and inversely proportional to the acceleration due to gravity.
Answer» Correct Answer - B Decrease in gravitational potential energy = Increase in rotational kinetic energy about an axis passing through end point `:. "mg"(l)/(2)=(1)/(2)((ml^(2))/(3))omega^(2)` `rArr` Angular velocity, `omega=sqrt((3g)/(l)) or omegaprop sqrt((g)/(l))`

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