Download Normal Force

What is the Normal Force (FN)?
The normal force is not...
...a force that's just like the other forces
...an ordinary force.
...an action-reaction force pair of an object's weight
The common meanings of the word "normal" do not apply. In the
case of the Normal Force what is actually being described is
geometry.
If two lines are at right angles to each other, we call them perpendicular
If two surfaces are at right angles to each other, we call them orthogonal.
If a surface and a line are at right angles to
each other, we say the line is normal. So any
line that is at a right angle to the surface is
called a normal line.
If there is a force coming from the
surface and at a right angle to the
surface then we call it a Normal line
Any force coming from the surface and
acting at a right angle to the surface is called
the Normal Force.
When an object is sitting on a level surface
then the normal force is always equal and
opposite of the weight of the object.
On an inclined surface notice that...
The angle of the incline and the
angle of the weight away from
the normal is the same size..
The weight continues to
act straight down toward
the center of the earth.
The normal force is equal
and opposite to the
perpendicular force.
The normal force is not always equal to the weight of
an object; it is the force pressing the surfaces
together.