A uniform chain of length 2 m 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 chain on the table?
- (A)7.2 J
- (B)3.6 J✓ Correct
- (C)120 J
- (D)1200 J
Answer: (B)
Solution
The part of the chain hanging over the edge has mass kg, and its centre of mass lies m below the table top. Lifting this portion back onto the table raises its centre of mass through m, so the work done is J.
JEE Main · 2004 · 24 Apr 2004 · Offline · Single correct option