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

Options

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

Answer

C

Explanation

Mass of length 2 m of the chain = 4 kg
Mass of length 60 cm or 0.60 m of the chain
`=(4xx0.60)/2=1.2 kg`
Weight of the hanging part of the chain = 1.2 x 10=12 N
Since the centre of gravity of the hanging part lies at its mid point, ie. 30 cm or 0.30 m
`therefore` W= 12 x 0.30= 3.6 J