Question

A uniform cable of mass ‘M’ and length ‘L’ is placed on a horizontal surface such that its (1/n)^th  part is hanging below the edge of the surface. To lift the hanging part of the cable upto the surface, the work done should be -

(1) nMgL

(2)  MgL/2n²

(3)  2MgL/n²

(4)  MgL/n²

Answer 1

Correct option  (2)  MgL/2n²

Explanation:

Work done against gravity 

= mgh