A uniform chain of length `2m` is kept on a table such that a length of `60 cm` hangas freely from the adge of the table . The table . The total mass of the chain ia `4 kg` What is the work done in pulling the entire the chain the on the table ?

Options

A. `12.9 J`
B. `6.3 J`
C. `3.6 J`
D. `2.0 J`

Answer

C

Explanation

Mass of length `2m` of the chain`= 4 kg`
mass of length `60 cn or 0.60 m` of the chain
`= (4 xx 0.60)/(2) = 1.2 kg`
Weight of the hanging part of the chain `= 1.2 xx 10`
`= 12 N`
Since of center gravity of the hanging part lines at its mid point, i.e. `30 cm or 0.30 = 3.6 J`