# Dictionary:Gravitational constant

Other languages:
English • ‎español • ‎中文（中国大陆）‎

The proportionality constant ${\displaystyle \gamma }$ in Newton's Law of Universal Gravitation. The gravitational force F between two point masses m1 and m2 can be related to the distance r between them:

${\displaystyle F={\frac {\gamma m_{1}m_{2}}{r^{2}}}}$

${\displaystyle \gamma }$ has the value ${\displaystyle 6.67\times 10^{-11}N\cdot m^{2}/kg^{2}}$. The force is a vector directed toward the attracting mass. The gravitational field g (also a vector, often called the acceleration of gravity) is the force per unit mass (measured by the force on the mass m1 in the gravimeter):

${\displaystyle g={\frac {F}{m_{1}}}={\frac {\gamma m_{2}}{r^{2}}}}$;

g is the vector sum of the effect of all the masses (e.g., the masses in the Earth).