5:Orbits are the result of a perfect balance between the forward motion of a body in space, such as a planet or moon, and the pull of gravity on it from another body in space, such as a large planet or star. ... These forces of inertia and gravity have to be perfectly balanced for an orbit to happen.
6;Gravity is the force that keeps planets in orbit around the Sun.
7.gravity
The dynamics of a rotating body is of course controlled by forces like gravity. Kepler's laws are a direct consequence of gravity
8.Rather, the term is derived from the concept of the tide "springing forth." Spring tides occur twice each lunar month all year long, without regard to the season. Seven days after a spring tide, the sun and moon are at right angles to each other
9.Neap tides occur halfway between each new and full moon – at the first quarter and last quarter moon phase – when the sun and moon are at right angles as seen from Earth.
