The gravity of the earth has two functions: one is the centripetal force required for the object to rotate with the earth, and the other is gravity. The farther you go to the poles, the smaller the centripetal force and the greater the gravity, so the greater the acceleration of gravity. Gravity acceleration, a physical term. The acceleration caused by gravity to a free fall is called gravity acceleration. If the mass of an object is expressed by m and the acceleration of gravity is expressed by g, the gravity g can be expressed as G=mg.

Brief introduction of gravity acceleration:

If a stone and an iron ball are allowed to fall freely from the same place and the same height at the same time, it can be observed that the speed of the two objects increases uniformly, changes in exactly the same way, and finally reaches the ground at the same time. This phenomenon shows that all free-falling objects in the same place on the earth have different weights, but the magnitude and direction of their acceleration in the process of falling are exactly the same.