Work is given: `W =- mgh`
where, `m = Volume xx Density`
`pir^(2)l xxd = (22)/(7) xx (0.5)^(2) xx 10 xx1`
`g = 980 cm s^(-2)`
`h = (10)/(2) = 5cm`
[The centre of mass of colume lies half way along its length `l`, therefore the centre of mass is raised to a height `h = (1//2)l`]
`:.W =- (22)/(7) xx (0.5)^(2) xx 10 xx 980 xx 5xx1`
`=- 38.5 xx 10^(3) erg =- 3.85 xx 10^(-3)J`
The nagative sign shows that systwm shows a decrease in internal enegry.
