| 释义 |
gravity Near the Earth's surface, a body experiences the gravitational force between the body and the Earth, which may be taken to be constant. The resulting acceleration due to gravity is −gk, where k is a unit vector directed vertically upwards from the Earth's surface, assumed to be a horizontal plane. The constant g, which is the magnitude of the acceleration due to gravity, is equal to GM/R2, where G is the gravitational constant, M is the mass of the Earth and R is the radius of the Earth. Near the Earth's surface, the value of g may be taken as 9.81 ms−2, though it varies between 9.78 ms−2 at the equator and 9.83 ms−2 at one of the poles.
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