Sir Isaac Newton was born in the same year that Galileo died. His accomplishments
include the development of the universal law of gravitation that explained the motion of
the planets, comets, and the moon and the nature of light and He also developed calculus.
Isaac Newton’s most famous and important work, the “Principa Mathmatica,” introduced
his 3 laws of motion.
• Newton’s 1st Law of Motion – Law of Inertia
A body continues in its state of rest, or of uniform motion in a straight line, unless a net
external force acts it upon.
(An object at rest or in motion stays at rest or in motion until an outside force act on it.)
• Newton’s 2nd Law of Motion – F=ma
When an unbalanced force acts on a body, the body will be accelerated.
(The Force exerted by an object is determined by its mass and acceleration.)
• Newton’s 3rd Law of Motion – Action/Reaction
All forces come in pairs. Every force is accompanied by an equal and opposite force.
(For every action there is an equal and opposite reaction.)