Definition of Force
Newton's first law of motion, we have that an
object will forever remain where it is kept unless a force is applied to move
it; and also that an object will continue to move along a straight line forever
at uniform speed unless a force is acted on it to change its speed and
Therefore, we can define force as:
An agent which
changes a body's state of rest or uniform motion along a straight line.
Force can broadly be divided into two groups, namely Contact
forces and force field.
Contact Forces: These are
forces that make contact with the bodies they impact. They include such forces
as forces of pull and push, tension, friction, and reaction.
Force Field: Unlike contact
forces, force fields do not make contact with the bodies they affect. They
impact bodies from a distance within their fields. Examples include
gravitational forces, electrical forces, and magnetic forces.
Force is a vector quantity. This means that it has
both magnitude and direction. In physics, things which have both magnitude and
direction are regarded as vector quantities.
Calculating Force: the
magnitude of force which acts on a body can be deduced by applying
Newton's second law of motion.
See calculation of force based on Newton's second
law of motion here.
Newton's First Law Of Motion