A thin uniform rod of mass m and length l is hinged at the lower end to a level floor and stands vertically. It is now allowed to fall, then its upper end will strike the floor with a velocity given by

Options

A. `sqrt(2gl)`
B. `sqrt(3gl)`
C. `sqrt(5gl)`
D. `sqrt(mgl)`

Answer

B

Explanation

`mg ((l)/(2)) = (1)/(2) I omega^(2)`
`rArr mg = (l)/(2)= (1)/(2) ((ml^(2))/(3)) ((v_(B))/(l))^(2)`
`v_(B)= sqrt(3gl)`