Hi, Recently I came across this image in deriving an equation for angle of repose of an object in an inclined plane: "W" is the weight of the component which acts vertically down. "Rn" is the normal reaction by the inclined plane "W cos alpha" is the component of the weight of the object parallel to the normal reaction. "alpha" is the angle of inclination of the plane. My question: In all calculations, I have observed the force component perpendicular to the tangent of contact point to be the maximum. Yes, I mean the resultant force. Whereas, in the above picturem such resultant force (W cos alpha) is smaller than the vertical component (W). How can this be right? Even if it is right, if I have to calculate the horizontal reaction by the plane, how can I calculate that? Pl. help. Thanks.