Posted by Kishore on .
Blocks A and B of weight 200N and 100N respectively, rest on a 30 inclined plane and are attached to the post which is held perpendicular to the plane by force P, parallel to the plane, Assume that all surfaces are smooth and that the cords are parallel to the plane. Determine the value of P. Also find the Normal reaction of Blocks A and B.

Engg Mechanics 
Henry,
Block A:
200*sin30 = 100 N. = Force parallel
to the plane.
Fn = 200*cos30 = 173.2 N. = Normal force
Block B:
100*sin30 = 50 N. = Force parallel to
the plane.
Fn = 100*cos30 = 86.6 N. = Normal force.
P = Wa+Wb = 200 + 100 = 300 N.