A body of mass 4kg rests in limiting equilibrium on a rouch plane whose slope is `30^(@)`. The slope is subsequently increased to `60^(@)`. Calculate (i) coefficient of limiting friction between the body and the surface, (ii) acceleration down the plane if coefficient of kinetic friction is 0.4, (iii) force required to prevent it from sliding down the plane, (iv) force required to just move it up the plane. `(g = 9.8 m//s^(2))`.
