EDIT: I think I just figured it out...could you check out the picture I added and see if my reasoning is right? Thanks!! http://img141.imageshack.us/img141/618/20080716103213jm3.png [Broken] ------------ I'm working on free-body diagrams and I'm having trouble finding the components of the weight of an object on an inclined plane. I know that if you take the +x axis to be the plane and the +y axis to be the direction of the normal force that the weight components are: W parallel = mgsin(theta) W perpendicular = mgcos(theta) where theta is the angle of inclination My problem is that I have trouble "seeing" geometrically how to actually FIND the components using trig functions. Is the weight -always- going to be determined by these two equations if I use the coordinate system that I mentioned? Sorry if this is too basic a question! I just wanted to see the "why" behind these equations.