Gravity is the force between any object and the Earth.
The force due to gravity acting on an object is called its weight ((W)), and acts downwards.
A body in free fall experiences an downwards acceleration of (g) = 9.8 mssup-2/sup.
Using (F = ma ), the equation of motion for an object of mass (m) kg with weight (W) N is:
(W = mg)
(W = mg)