lA fixed wedge ABC is an the shape of an equilateral triangle of side l initially, a chain of length 2l and mass m rests the wedge as shown. The chain is slowly being pulled down by the application of a force F as shown. Work done by gravity till the time the chain leaves the wedge will be:

Options

A. `-(((sqrt(3)+1)mgl)/(2))`
B. `(((sqrt(3)+1)mgl)/(2))`
C. `-(((sqrt(3)+1)mgl)/(4))`
D. `(((sqrt(3)+4)mgl)/(4))`

Explanation

Change in positive of CMN in vertical direction
`(Deltah)=(l(cos30^(@))/(2))+l`
work done by gravity
`=mg Delta=+mg((lsqrt(3))/(4)+l)`

`=+mg(l(sqrt(3)+4)/(4))`