Force
1. In physics, a force is an influence that can change the motion of an object.
2. Force is a quantitative description of an interaction that causes a change in an object's motion. An object may speed up, slow down, or change direction in response to a force. Put another way, force is any action that tends to maintain or alter the motion of a body or to distort it.
There are four fundamental forces that govern the interactions of physical systems. Scientists continue to pursue a unified theory of these forces:
1. Gravitation: the force that acts between masses. All particles experience the force of gravity. If you hold a ball up in the air, for example, the mass of the Earth allows the ball to fall due to the force of gravity. Or if a baby bird crawls out of its nest, the gravity from the Earth will pull it to the ground. While the graviton has been proposed as the particle mediating gravity, it has not yet been observed.
2. Electromagnetic: the force that acts between electrical charges. The mediating particle is the photon. For example, a loudspeaker uses the electromagnetic force to propagate the sound, and a bank's door locking system uses electromagnetic forces to help shut the vault doors tightly. Power circuits in medical instruments like magnetic resonance imaging use electromagnetic forces, as do the magnetic rapid transit systems in Japan and China –called "maglev" for magnetic levitation.
3. Strong nuclear: the force that holds the nucleus of the atom together, mediated by gluons acting on quarks, antiquarks, and the gluons themselves. (A gluon is a messenger particle that binds quarks within the protons and neutrons. Quarks are fundamental particles that combine to form protons and neutrons, while antiquarks are identical to quarks in mass but opposite in electric and magnetic properties.)
4. Weak nuclear: the force that is mediated by exchanging W and Z bosons and is seen in beta decay of neutrons in the nucleus. (A boson is a type of particle that obeys the rules of Bose-Einstein statistics.) At very high temperatures, the weak force and the electromagnetic force are indistinguishable.
Словник Cambridge Dictionary https://dictionary.cambridge.org/
Англійський словник Коллінза, https://www.collinsdictionary.com/
ThoughtCo. Dictionary https://www.thoughtco.com/definition