NASA Logo - Web Link to

+ Text Only Site
+ Non-Flash Version
+ Contact Glenn

Computer drawing of a rocket engine demonstrating Newton's Third Law of Motion.

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 re-action, 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
  • Button to Display Previous Page Newton's Laws of Motion: Button to Return to Guided Tour Page
  • Button to Display Previous Page Propulsion System: Button to Display Next Page

Rocket Propulsion Activity: Grade 9-10
Fundamental Terminology: Grade 10-12
Hero Engine: Grade 6-10
Rocket Car: Grade 6-10
Rocket Pinwheel: Grade 6-10
Newton Car: Grade 10-12

Related Sites:
Rocket Index
Rocket Home
Beginner's Guide Home


     First Gov Image

+ Inspector General Hotline
+ Equal Employment Opportunity Data Posted Pursuant to the No Fear Act
+ Budgets, Strategic Plans and Accountability Reports
+ Freedom of Information Act
+ The President's Management Agenda
+ NASA Privacy Statement, Disclaimer,
and Accessibility Certification


NASA Logo   
Editor: Tom Benson
NASA Official: Tom Benson
Last Updated: Jun 12 2014

+ Contact Glenn