Isaac Newton's Three Laws of Motion, first published in 1684, was the
cornerstone of Physics studies for nearly 250 years (before being
usurped by the discoveries of Albert Einstein), and remain to this day
one of the most practical pieces of knowledge in the world.
Simply stated, the three laws are:
1. Every object in a state of uniform motion tends to remain in that
state of motion unless an external force is applied to it.
2. The relationship between an object's mass m, its acceleration a,
and the applied force F is F = ma. Acceleration and force are vectors
(as indicated by their symbols being displayed in slant bold font); in
this law the direction of the force vector is the same as the
direction of the acceleration vector.
The Second Law can also be restated as "The acceleration of an object
as produced by a net force is directly proportional to the magnitude
of the net force, in the same direction as the net force, and
inversely proportional to the mass of the object."
3. For every action there is an equal and opposite reaction.
A detailed explanation of these laws, as well as practical examples
and illustrations on these concepts can be found at
Newton's Three Laws of Motion
Newton's Laws of Motion Tables of Contents
Sir Isaac Newton
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