The gravity of the earth comes from the gravity of the earth, and the objects on the surface of the earth are partly the gravity we perceive and partly the centripetal force that rotates with the earth.

Gravity is one of the inherent properties of mass. Every object is bound to attract each other. Although the nature of gravity has yet to be determined, people have long realized its existence and function. Objects close to the earth are attracted to the center of mass of the earth without exception. Because any object on the surface of the earth is really insignificant compared with the mass of the earth itself.

Extended data:

The value of gravity acceleration varies according to the altitude and latitude of different places. The acceleration of gravity is related to the mass of the moon. The gravity of the earth is formed by adding the mass of the moon. Without the moon's gravity, it is not 9.78033, and the acceleration of gravity is also related to the mass of the moon.

The unit of gravity acceleration should also be "N.S" Newton N(kg.m/s). For example, in terms of sea level, the gravity acceleration at the equator of the earth is 9.78033N·S2, and that at the North Pole is about 9.83N.S2? . Generally speaking, at the same height, the gravitational acceleration at the equator is the smallest, while the gravitational acceleration at the poles is the largest. )

Before 1935, the World Meteorological Organization took the acceleration of gravity g as 9.8 m/s2. After 1935, WMO takes the sea level of 45 north latitude as the benchmark and takes g as 9.80665 m/s2. (It can be written as g45)

But due to the progress of measurement technology, g45? The value of is no longer 9.80665 kg.m/s2. Constant g = 9.80665 m/s2? On the premise of, now take the gravity acceleration of sea level and latitude 45.542 as the reference value of G, which is the general M.K.S unit.

References:

Baidu encyclopedia gravity