Gravity
Reference from the original Physics I textbook.
- Gravity
The force of attraction between two masses. This force keeps the Earth in orbit around the Sun, as well as keeps your feet firmly planted upon the ground.
- Related Glossary Terms
Force of Gravity Equation, Gravitational Force Equation, Weightⓘ, Weight Equation
- Index
Glossary and deeper reading · 2 refreshers
These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.
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Gravity
Gravity is the attractive interaction between masses in the Newtonian model. For spherical bodies or point-mass approximations, its strength decreases with the square of the separation between their centers. For example, Earth’s gravity provides the inward force that keeps a satellite in orbit.
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Weight
Weight is the gravitational force exerted on an object by a specified attracting body. Near Earth’s surface its magnitude is approximately mass times the local gravitational field strength, and it is measured in newtons. For example, an astronaut has less weight on the Moon while retaining the same mass.