Gravity is a fundamental force of attraction that exists between any two objects with mass or energy. It keeps planets in orbit around stars, moons in orbit around planets, and causes objects to fall to the ground when dropped. This invisible force shapes the structure of our universe.
Newton's Law of Universal Gravitation is the primary formula describing gravity. It states that F equals G times m one times m two divided by r squared. Here F is the gravitational force in Newtons, G is the universal gravitational constant approximately 6.674 times 10 to the negative 11, m one and m two are the masses of the objects in kilograms, and r is the distance between their centers in meters.
Gravitational acceleration is derived from Newton's law and calculates the acceleration experienced by an object due to gravity. The formula is g equals G times M divided by r squared. Here g is the acceleration due to gravity in meters per second squared, G is the universal constant, M is the mass of the larger object like a planet, and r is the distance from the center. On Earth's surface, g is approximately 9.8 meters per second squared.
Gravity is responsible for orbital motion throughout the universe. For stable orbits, the gravitational force equals the centripetal force. This gives us G times M times m divided by r squared equals m times v squared divided by r. Solving for velocity, we get v equals the square root of G times M divided by r. This explains how satellites orbit Earth, how planets orbit the Sun, and how gravity creates tidal forces.
To summarize what we've learned about gravity: It is a fundamental force of attraction between all objects with mass. Newton's Law of Universal Gravitation gives us the formula F equals G times m one times m two divided by r squared. Gravitational acceleration is calculated as g equals G times M divided by r squared, with Earth's surface gravity being approximately 9.8 meters per second squared. These principles govern everything from falling objects to planetary orbits throughout our universe.