6.1 | Newtonian Gravitation

universal law of gravitation

There is gravitational attraction between any two objects. If the objects have masses m1 and m2, and their centres are separated by a distance r, the magnitude of the gravitational force on either object directly proportional to the product of m1 and m2, and inversely proportional to the square of r

inverse-square law

a mathematical relationship in which one variable is proportional to the inverse of the square of another variable

gravitational field

a collection of vectors that determines the magnitude and direction of the gravitational force

gravitational field strength

is the force of attraction per unit mass of an object placed in a gravitational field

satellite

an object or a body that revolves around another body that usually has much more mass than the satellite due to gravitational attraction

orbital radius

the distance between the centre of satellite and the centre of its parent body

geosynchrounous orbit

the orbit around Earth of an object with an orbital speed matching the rate of Earth’s rotation; period of such an orbit is exactly one Earth day

geostationary orbit

a type of geosynchronous orbit in which the satellite orbits directly over the equator (it will appear to remain fix in the same point in sky)