Question

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

(1) 1200 J

(2) 3.6 J

(3) 120 J

(4) 7.2 J

Answer 1

Answer is (2) 3.6 J

W = mgh

where h is the distance moved by centre of gravity

W = 0.6 x (4/2) x 9.8 x 0.3 = 3.6 J