ys varun.tinkle
now it comes...

from my equn. of n, you'll get
T - nsin = M'a
=>T = M'a + nsin
=> T = M'a + (masin + mgcos).sin
        = M'g.tan + mg.tan.sin² + mg.cos.sin ..... using a = g.tan
        = M'g.tan + mg (tan.sin² + cos.sin)

        = M'g.tan + mg (sin³/cos + cos.sin)

        = M'g.tan + mg ( sin³ + cos².sin ) / cos

        = M'g.tan + mg (sin/cos).(sin² + cos²)

        = M'gtan + mg.tan

        = (M'+m).g.tan

 

use this in Mg - T = Ma

or M = T/(g - a) to get the answer....

 

 

 

 

This proves... ur mistake was in n + ma.sin = mg.cos

it should be n = ma.sin + mg.cos

because ma.sin is the component of pseudo force on m along mg.cos

 

 

 

whoaaaaaaaa!!!!