Newton's law of universal gravitation

Newton's universal law of gravitation is a physical law that describes the attraction between two objects with mass. It is talked about in Isaac Newton's Philosophiae Naturalis Principia Mathematica.^[1][2] The law is part of classical mechanics.

The formula is

${\displaystyle F_{g}=G{\frac {m_{1}m_{2}}{r^{2}}},}$

In this equation:

• ${\displaystyle F_{g}}$ is the total gravitational force between the two objects.
• ${\displaystyle G}$ is the gravitational constant.
• ${\displaystyle m_{1}}$ is the mass of the first object.
• ${\displaystyle m_{2}}$ is the mass of the second object.
• ${\displaystyle r}$ is the distance between the centers of the objects.

In SI units, ${\displaystyle F_{g}}$ is measured in newtons (N), ${\displaystyle m_{1}}$ and ${\displaystyle m_{2}}$ in kilograms (kg), ${\displaystyle r}$ in meters (m), and the constant ${\displaystyle G}$ is approximately equal to 6.674×10⁻¹¹ N m² kg⁻².^[3]