When an object is at rest on a horizontal surface, such as a table, it has weight but is not accelerating. In this situation, the weight of the object is not an unbalanced force. In fact, the net force on the object is zero! Therefore, another force, which serves to balance the effects of gravity, must be present on the object. The origin of this supporting force is the surface itself, and this force is responsible for the contact between the object and the surface. Since this second force is perpendicular to both the object and the surface, it is called a normal force. (In mathematics, the word normal is used to describe lines that are perpendicular.) We represent the normal force by the symbol FN . The diagram below represents the relationship between the weight of an object and the normal force on it. 8. How does the magnitude of the normal force compare with the weight of the object in the diagram shown above?
The magnitude of the normal force is equal to the weight of the object in the diagram shown above. This is because the normal force is acting perpendicular to the surface in order to support the weight of the object and maintain equilibrium.
