# Newton's Laws

In Glogpedia

Last updated 6 years ago

Discipline:
Science
Subject:
Physics
8   Newton's Laws

1st Law

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Sir Isaac Newton

2nd Law

CJ Sturgess

An object that is not moving remains at rest until something pushes or pulls it. An object that is moving remains moving until something pushes or pulls it. All objects resist having their motion changed. This tendency to resist a change in motion is called inertia. The more mass an object has, the greater its inertia.

When one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object. The force exerted by the first object is the action force. The force exerted by the second object is the reaction force.

A change in motion occurs only if a net force is exerted on an object. A net force changes the velocity of the object, and causes it to accelerate. If an object is acted upon by a net force, the change in velocity will be in the direction of the net force. The acceleration of an object depends on its mass. The more mass an object has or the more inertia it has, the harder it is to accelerate. More mass means less acceleration if the force acting on the objects is the same.

3rd Law

I. Newton's first law of motion says that an object in constant motion will stay in motion and an object at rest will stay at rest unless acted on by an unbalanced force.

II. The second law of motion states that the force of an object is equal to its mass times its acceleration. (f = ma)

III. Newton's third law of motion states that for every action there is an equal and opposite reaction.

Khan Academy explains how the 1st law works.

In this video, the 2nd law is illustrated with air cannons.

And, finally, the 3rd law is illustrated with a skateboard and a small rocket.