We have derived the equation of g (acceleration due to gravity) and we will use that formula or equation to find out its value. The formula we will use is: *g = GM/*R^{2}**[Derivation of g formula here]**

**Value of g from its formula**

We will use 3 values in the formula. And those values are for the mass of the earth M, the radius of the earth R, and universal gravitational constant G.

*Mass of the earth = M=6 × 10 ^{24} kg*

*Radius of the earth = R=6.4 × 10*^{3}km = 6.4 × 10^{6}m.**=**

*G =*universal gravitational constant**N m**

*6.67 x 10*^{-11 }^{2}kg

^{-2}

Putting the values of M, R and G we get:

*g = GM/*R^{2}=(*6.67 x 10*^{-11})x(6 × 10^{24})/( 6.4 × 10^{6})^{2}= 9.77m/s^{2}The value of ‘g’ calculated above is near the equator at sea level. The value of ‘g’ varies with height, depth, and latitude. See here

**how the value of g changes with height and depth**.