A term convenient in interior ballistic theory, which
is defined as the product of the number of moles of
gas per gram of propellant and the adiabatic-constant-volume
flame temperature. The term force comes from the Latin
word for strength.
In physics force
is defined by Newton's laws of motion and a
force is considered that which can impose a change
of velocity on a material body. In physics force is
described as a quantity that produces a change in
the size or shape (strength of materials) or the motion
of a body.
Commonly experienced as a push
or pull, force is a vector quantity,
having both magnitude and direction.
Four basic types
of force are known in nature. The gravitational force
(Gravitation) and the electromagnetic force (Electricity;
Magnetism) both have an infinite range. The strong
nuclear force, or strong interaction, is a short-range
force holding the atomic nucleus together, and the
weak nuclear force or weak interaction, is a short-range
force associated with radioactivity and particle decay.
Scientists have not been able to confirm the existence
of a hypothesized fifth force, a weak force supposed
to counteract gravitation.