Fsin q . This is because the part of the force that actually causes turning is the component at right angles. Hence, moments have direction and so are vectors. Mass and weight Mass is a scalar quantity, giving the amount of matter that a body has. It's unit is the kilogram.
Weight is a vector quantity, giving the gravitational force that acts downwards on a mass.
It has the unit of force which is the Newton. In space you lose your weight, but not your mass. A child, of mass 20kg, is sitting on the left side of a see-saw. The child is 2.4m along the plank from the fulcrum. Find the moment of the child's weight.