Forces and Vectors
In order for the inertia of an object to change an outside force must be applied
to that object.
A force is any push or
Forces are constantly being applied to objects. The sum of all these forces is the net
force and if the net force equals zero the object is in equilibrium.
∑ F = net force
If the object is moving it is in dynamic equilibrium and if the object is at rest it is in
Forces are measured in newtons. A newton is one
kilogram meter per second per second. (1 kg · m/s2)
Forces are also vector quantities. A vector has both
direction and magnitude.
A scalar has only magnitude.
Since physics deals with vectors you need to understand how physics deals with direction. Direction is
put into terms of negative and positive combined with angles.