Acceleration Due To Gravity (Also seen in GCSE Physics 2)

An object that falls freely will accelerate towards the Earth because of the force of gravity acting on it.

The size of this acceleration does not depend mass, so a feather and a bowling ball accelerate at the same rate. On the Moon they hit the ground at the same time, on Earth the resistance of the air slows the feather more than the bowling ball.

The size of the gravitational field affects the magnitude of the acceleration. Near the surface of the Earth the gravitational field strength is 9.81 N/kg. This is also the acceleration a free falling object would have on Earth. In the equations of motion a = g = 9.81 m/s.

Mass is a property that tells us how much matter it is made of.

Mass is measured in kilograms, kg

Weight is a force caused by gravity acting on a mass:

weight = mass x gravitational field strength

Weight is measured in Newtons, N