Quantity	Definition	Formula	Unit
Force	a pull or a push	mass x acceleration	Newton (N)
Moment	turning effect of a force about a fixed point (pivot)	force x perpendicular distance from pivot	Newtonmetre (Nm)
Centre of Gravity  (Centre or Mass)	point at which the entire weight of the object seems to act	-	-
Principle of Moments	when in equilibrium (balanced),  anticlockwise  = clockwise moments	anticlockwise  = clockwise moments	-