Isaac Newton formulated three laws that describe fundamental properties of physical reality

• Isaac Newton developed three principles, called the laws of motion, that apply to the motions of objects on Earth as well as in space

• These are

  • the law of inertia: a body remains at rest, or moves in a straight line at a constant speed, unless acted upon by a net outside force
  • F = m x a (the force on an object is directly proportional to its mass and acceleration)
  • the principle of action and reaction: whenever one body exerts a force on a second body, the second body exerts an equal and opposite force on the first body