the magnitude of the acceleration due to gravity on Earth. [P2.3, P3.2]
is: a vector quantity. [M2.4]
is: the gravitational force exerted on an object by the Earth (or the Moon or some other massive body). [M2.4, P2.3, P2.6]
has direction: from the centre of mass of the object towards the centre of the Earth. Near the surface of the Earth, the weight of an object acts vertically downwards. [P2.3, P3.2]
has magnitude: given by the product of the object's mass and the magnitude of the acceleration due to gravity on Earth. [P2.3, P3.2]
more strictly, is: the resultant gravitational force exerted on the object by all other objects in the Universe. [P3.1]
Copyright 1997, The Open University