When a force is called a "normal" force,it is
A) the usual force expected given the arrangement of a system.
B) a force that is perpendicular to the surface of the Earth at any given location.
C) a force that is always vertical.
D) a contact force perpendicular to the contact surfaces between two solid objects.
E) the net force acting on a system.

Question

Quizplus · Accepted Answer

The definition of a normal force is that it is a contact force perpendicular to the contact surfaces between two solid objects. Therefore, the best choice is D.

When a Force Is Called a "Normal" Force,it Is