A body having a weight is placed on a smooth plane inclined to the horizontal at an angle of .
Given that the body is kept in equilibrium under the action of a force having a magnitude of N,
which is acting upwards in the direction of the line of greatest slope, find the magnitude of and the reaction of the plane on the body.
The system is in equilibrium under three forces; weight, reaction, and an action force parallel to the plane.
By applying Lami's rule, we get