* The normal force on a body is generally associated with the force that the surface of one body exerts on the surface of another body in the absence of any frictional forces between the two surfaces.
* The normal force is always perpendicular to the surfaces in contact. This is the origin of its name - normal to the surface.
* The normal force is an action-reaction force. A surface will not exert a normal force on an object in contact with it unless some other external force pushes the object into the surface.
* The atoms in the surface are compressed microscopically to create the normal force. The surface deforms imperceptibly and produces a reaction force equal to the force pressing the object into the surface.
* For an object sitting on a horizontal surface, the normal force will be equal to the weight of the object.
* The normal force is not always equal to the weight of an object; it is the force pressing the surfaces together.
