|Source: University of Alaska at Fairbanks physics dept.|
F1 is pretty simple and most people can understand that gravity is pulling you down to the earth. F2, the normal force, is the force be applied to the rectangle by the ramp. The theory is that for every action there is an opposite and equal reaction. So fs you press down on a floor, then the floor is "pressing" back against you. Now this is a really simple explanation and not technical so don't try to over think it unless you are like me. F3 is the friction. Friction helps keep the rectangle from sliding down the ramp so is acting up the ramp.
This is how I see the world. When something is moving or remaining stationary, I am thinking about the forces acting on the object and imagining the arrows. When I see a tree blowing in the wind I am thinking about the tension in the limb, the wind moving the limbs, and the other various forces in motion.
This is how I look at the world, but not the only way. How do see the world at work?