What does Newton's law of gravitation describe?

Newton's law of gravitation describes the force of attraction between two masses and how it depends on their distance apart.

Newton's law of gravitation, also known as Newton's law of universal gravitation, is a fundamental principle that has greatly contributed to our understanding of the physical world. It was first formulated by Sir Isaac Newton in the 17th century and is a cornerstone of classical physics.

The law 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 can be mathematically expressed as F = G * (m1*m2)/r², where F is the force of attraction between the masses, m1 and m2 are the two masses, r is the distance between the centres of the two masses, and G is the gravitational constant.

This law explains why objects fall to the ground when dropped, why the planets orbit the sun, and why the moon orbits the Earth, among other phenomena. It implies that the force of gravity decreases rapidly with increasing distance, but never completely disappears, no matter how far apart two masses are.

The concept of universal gravitation was revolutionary at the time of its introduction, as it provided a unified explanation for terrestrial and celestial phenomena that had previously been treated separately. It also laid the groundwork for the development of the theory of general relativity by Albert Einstein in the 20th century, which further refined our understanding of gravity.

However, it's important to note that Newton's law of gravitation is an approximation that works well for most practical purposes, but it doesn't fully explain certain phenomena, such as the precession of the perihelion of Mercury's orbit. For these more complex situations, Einstein's theory of general relativity provides a more accurate description.

In your studies of physics, you'll find that Newton's law of gravitation is a powerful tool for understanding a wide range of phenomena, from the motion of planets in our solar system to the behaviour of galaxies in the universe.