Which of the following forces is not a fundamental force in physics?

The frictional force is not considered a fundamental force in physics. Instead, it is a macroscopic force that arises from the interactions between surfaces in contact, primarily due to electromagnetic interactions at the atomic level. Fundamental forces, on the other hand, are the basic interactions that govern the behavior of matter and energy in the universe, and they are not derived from other forces.

The four fundamental forces in physics are the gravitational force, which governs the attraction between masses; the electromagnetic force, which acts between charged particles; the weak nuclear force, responsible for certain types of radioactive decay; and the strong nuclear force, which holds protons and neutrons together in atomic nuclei. Each of these fundamental forces operates at a fundamental level, influencing the behavior of matter without depending on other forces.

Understanding this distinction helps clarify the nature of interactions in physics and emphasizes the unique role of fundamental forces compared to emergent forces like friction.