Question

Give at least two points of difference between G and g.

Answer 1

Both G and g are used while performing the calculations involving problems related to gravitational forces and problems involving the motion of a body under the influence of external forces.

Complete step by step answer:
(1) G is the gravitational constant involved in the universal law of gravitation while g is the value of acceleration due to gravity.
(2) The value of G is $6.67\times {{10}^{-11}}N{{m}^{2}}k{{g}^{-2}}$ while the value of g is $9.8m/{{s}^{2}}$. The value of G remains constant everywhere in the universe while the value of g varies from place to place. On earth, its value is $9.8m/{{s}^{2}}$ while on moon its value is one-sixth the value on earth.

Additional Information:
The gravitational constant is the proportionality constant used in Newton’s Law of Universal Gravitation, and is commonly denoted by G. This is different from g, which denotes the acceleration due to gravity.
Also, there is a relationship between G and g which on the earth’s surface is given by $g=\dfrac{G{{M}_{e}}}{{{R}^{2}}_{e}}$,
Where ${{M}_{e}}$ is the mass of the earth and R is the radius of the earth.

Note: Most of the times we get confused between G and g. One is a constant in a sense used only while determining the value of gravitational force acting on one body due to another on the other hand g is the acceleration due to gravity and a body falling freely under the influence of gravity has a value of acceleration equal to g.