A metre stick is held vertically with one end on the floor and is then allowed to fall. If the end touching the floor is not allowed to slip, the other end will hit the ground with a velocity of `(g=9.8"m/s"^(2))`

Options

A. `3.2` m/s
B. `5.4` m/s
C. `7.6` m/s
D. `9.2` m/s

Answer

B

Explanation

Law of conservation energy -
`mgh=(1)/(2)Iomega^(2)`
implies `mg((l)/(2))=(1)/(2)Iomega^(2)=(1)/(2)(ml^(2))/(3)((v_(B))/(l.l))^(2)`
implies `v_(B)=sqrt(3gl)=sqrt(3xx9.8xx1)=5.4` m/s