Question on: SS1 Physics - Laws of Motion

The normal force is a contact force exerted by a surface on an object that is in contact with it. Newton's third law of motion states that for every action, there is an equal and opposite reaction. In the case of the normal force, when an object exerts a downward force due to its weight, the surface exerts an equal and opposite upward force as the normal force. This reaction force prevents the object from sinking to the surface.