Sir Isaac Newton first presented his three laws
of motion in the "Principia Mathematica Philosophiae Naturalis"
in 1686. His third law states that for every action (force) in nature
there is an equal and opposite reaction. In other words, if object A
exerts a force on object B, then object B also exerts an equal and
opposite force on object A. Notice that the forces are exerted on
different objects.
In aerospace engineering, the principal of action and reaction is very
important. Newton's third law explains the generation of
thrust
by a rocket engine. In a rocket engine, hot exhaust gas
is produced through the
combustion
of a fuel with an oxidizer.
The hot exhaust gas flows through the rocket
nozzle
and is accelerated to the rear of the rocket. In reaction, a thrusting force
is produced on the engine mount.
The thrust accelerates the rocket as described by Newton's
second law
of motion.
Guided Tours

Newton's Laws of Motion:

Propulsion System:
Activities:
Rocket Propulsion Activity: Grade 910
Fundamental Terminology: Grade 1012
Hero Engine: Grade 610
Rocket Car: Grade 610
Rocket Pinwheel: Grade 610
Newton Car: Grade 1012