A uniform chain of length 4m is kept on a table such that a length of 120 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 chain on the table ?

Explanation

Fraction of length of the chain hanging from the table
That` " " (L)/(x)=120 cm`
`implies x=(10)/(3)`
Work done in pulling the chain on the table

or` " " v=-m'g (60 cm)`
`=-((4)/(400 cm)xx120 cm)g (60 cm)`
`W=(mgL)/(2x^(2))=(4xx10xx4)/(2xx(10//3)^(2))=72 J`