gravity, or gravitation is the common name for gravitational force.
gravity, or gravitation is the common name for gravitational force.
what is the common name for gravitational force?
gravity , or gravitation
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the tidal force on earth due to a perturbing body (sun, moon or planet) is expressed by newton's law of universal gravitation, whereby the gravitational force of the perturbing body on the side of earth nearest is said to be greater than the gravitational force on the far side by an amount proportional to the difference in the cubes of the distances between the near and far sides. if the gravitational force of the perturbing body acting on the mass of the earth as a point mass at the center of earth ( which provides the centripetal force causing the orbital motion ) is subtracted from the gravitational force of the perturbing body everywhere on the surface of earth, what remains may be regarded as the tidal force. this gives the paradoxical notion of a force acting away from the satellite but in reality it is simply a lesser force towards that body due to the gradient in the gravitational field. for precession, this tidal force can be grouped into two forces which only act on the equatorial bulge outside of a mean spherical radius. this couple can be decomposed into two pairs of components, one pair parallel to earth's equatorial plane toward and away from the perturbing body which cancel each other out, and another pair parallel to earth's rotational axis, both toward the ecliptic plane. the latter pair of forces creates the following torque vector on earth's equatorial bulge:
axial precession