How is gravitational force calculated in physics?

Gravitational force is calculated using Newton's law of universal gravitation, which involves the masses and distance between objects.

In more detail, Sir Isaac Newton's law of universal gravitation states that every particle of matter in the universe attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres. This is often summarised as: F = G * (m1 * m2 / r^2), where F is the force of attraction between the masses, G is the gravitational constant, m1 and m2 are the two masses, and r is the distance between the centres of the two masses.

The gravitational constant (G) is a key part of this equation. It is a proportionality constant used in the equation, and its value is approximately 6.674 x 10^-11 N(m/kg)^2. This constant is extremely small, which is why we don't feel the gravitational pull from everyday objects around us, but only from very large masses like the Earth.

The masses (m1 and m2) are simply the masses of the two objects that are attracting each other. These can be anything from two atoms to two planets. The larger the masses, the greater the force of attraction.

The distance (r) is the distance between the centres of the two masses. This is squared in the equation, which means that the force of gravity decreases rapidly as the distance increases. This is why, for example, astronauts in space experience much less gravitational force than we do on the surface of the Earth.

In summary, the gravitational force between two objects can be calculated using the masses of the objects, the distance between them, and the gravitational constant. This equation allows us to predict the movements of planets and stars, and is fundamental to our understanding of the universe.