In the figure shown there is a fixed wedge 'W' of inclination `theta`. `A` is a block, `B` is a disc and 'C' is a solid cylinder. `A,B,C` each has mass 'm'. Assuming there is no sliding anywhere and string to be of negligible mass find :
The fricition force acting on the cylinder due to the wedge is `(mg)/15(1+n sin theta)` that `n` is

Answer

7

Explanation

`(a) mg-T_(1)=ma ....(1)`
`rArrT_(2)+f-mg sin theta=ma/2.....(2)`
`(T_(2)-f)r=1/2mr^(2)xxa/(2r)....(3)`

`rArr(T_(1)-T_(2))r =1/2mr^(2)xxa/r......(4)`
By `(1),(2),(3) & (4)`
`rArra =(4 g (2- sin theta))/15` substitute this a value we get
`f=(mg)/15 (1-7) sin theta`