# data[].attributes.attachment_link.description
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.

# data[].attributes.attachment_link.readable_text
This page is intended for college, high school, or middle school students. For younger students, a simpler explanation of the information on this page is available on the Kids Page.

Sir Isaac Newton first presented his three laws of motion in the "Principia Mathematica Philosophiae Naturalis" in 1686. His first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This is normally taken as the definition of inertia. The key point here is that if there is no net force resulting from unbalanced forces acting on an object (if all the external forces cancel each other out), then the object will maintain a constant velocity. If that velocity is zero, then the object remains at rest. And if an additional external force is applied, the velocity will change because of the force. The amount of the change in velocity is determined by Newton's second law of motion.

There are many excellent examples of Newton's first law involving aerodynamics. The motion of an airplane when the pilot changes the throttle setting of the engine is described by the first law. The motion of a ball falling down through the atmosphere, or a model rocket being launched up into the atmosphere are both examples of Newton's first law. The motion of a kite when the wind changes can also be described by the first law. We have created separate pages which describe each of these examples in more detail to help you understand this important physical principle.
Activities:
Guided Tours
Newton's Laws of Motion:

Navigation ..

Beginner's Guide Home Page

# data[].attributes.attachment_link.description
This page is intended for college, high school, or middle school students. For younger students, a simpler explanation of the information on this page is available on the Kids Page. Sir Isaac Newton first presented his three laws of motion in the "Principia Mathematica Philosophiae Naturalis" in 1686.

# data[].attributes.body
There is an equal and opposite reaction for every force of nature.

The law of action and reaction.

Examples: if i threw a ball in the air it would be an action and the reaction is the ball falling back down.

# data[].attributes.body
Force is equal to the change in momentum as well as change in time.

Also known as the Law of Force and Acceleration.

Examples: Pushing one block of cement would have more acceleration than pushing 2 blocks of cement cause it has less mass

# data[].attributes.body
All objects will remain at rest or in uniform motion in a straight line unless it is enforced to change state by using force.

Also known as inertia.

Examples: Kicking a soccer ball but stopped by kicking into the net.