重力

Gravitational force is the attractive force between two objects with mass. Every object in the universe attracts every other object, with the strength of this attraction depending on the masses involved and the distance between them. This fundamental force governs interactions from falling objects to celestial bodies orbiting in space.

Gravitational force decreases as the distance between two objects increases. The relationship follows an inverse square law: if you double the distance, the gravitational force becomes one-quarter as strong. This principle explains why gravitational effects are strongest between nearby objects and weaker across vast cosmic distances.

Mass is the primary factor determining gravitational force strength between objects. Objects with greater mass exert stronger gravitational attraction on other objects. The force is directly proportional to both masses involved, meaning doubling either mass doubles the gravitational force between them.

Weight is the gravitational force exerted on an object by a celestial body, typically Earth. While gravitational force is a universal attraction between any two masses, weight specifically measures how strongly a planet or moon pulls on an object. Your weight changes on different celestial bodies, but your mass remains constant.

The universal law of gravitation describes how all objects attract each other based on mass and distance. This law explains why planets orbit stars and moons orbit planets in predictable paths. The gravitational force provides the centripetal acceleration needed to keep celestial bodies in stable orbital motion.

A gravitational field represents the region of space where a massive object exerts gravitational influence on other objects. Every mass creates its own gravitational field, which extends infinitely but weakens with distance. This concept helps visualize how gravity acts across space without requiring direct contact between objects.