1. The Normal Force
The normal force is a force that opposes the Earth’s gravitational attraction and is perpendicular to the surface that an object rests or is moving on.
For a horizontal surface, FN = Fg = mg.
For a surface that is not perpendicular to gravity, FN = Fgcos FN 

2. The Normal Force  = 0 FN FN Fg Fg FN = Fg = mg
Is there any component of gravity parallel to the surface?

3. The Normal Force  = 90 FN Fg What is the force of friction?
What is the normal force equal to?
How much of the force of gravity is directed parallel to the plane?

4. The Normal Force  FN FN Fg Fg FN = Fg = mg FN = Fg cos = mg cos
cos = adj/hyp Fg
FN = Fg = mg
FN = Fg cos = mg cos

5. Given a block on an inclined plane, show how the force diagram relates to the physical representation.
FN = Normal Force 1 1
Fg,h = Component of acceleration of gravity parallel to the plane FN 2 2
Fg = mg = weight
Fg,v = Component of acceleration of gravity perpendicular to the plane
Force Diagram 2 Fg
Note that Fg,y is equal in magnitude to the Normal force, but of opposite direction. FN = Fg,y = Fg cos (angle 2)
Fg,p = Fg sin (angle 2)
Fg,v
Fg,h

6. The Normal Force  FN = Fg cos = mg cos FN FN Fg Fg FN = Fg = mg
cos = adj/hyp Fg
FN = Fg = mg
Fg,x = Fg sin = mg sin