NCEA Level 3 Physics – Mechanics Practice Exam

The concept that refers to the force exerted by a spring when it is compressed or stretched is known as the restoring force. This force is a consequence of Hooke's Law, which states that the force exerted by a spring is proportional to its displacement from the equilibrium position, and it acts in the opposite direction to the displacement. Therefore, when a spring is compressed or extended, the restoring force works to bring the spring back to its natural length. This characteristic behavior is fundamental to the way springs function in various physical systems and applications.

Other forces listed, such as gravitational, frictional, and applied forces, play different roles in mechanics. Gravitational force relates to the attraction between masses, frictional force involves resistance to motion between surfaces, and applied force is any force that is applied to an object. However, none of these specifically describe the behavior of springs when they are deformed.