NEWTON'S LAW

NEWTON'S LAWS

Newton's laws of motion are three physical laws that, together, laid the foundation for classical mechanics . They describe the relationship between a body and the forces acting upon it, and its motion in response to those forces. More precisely, the first law defines the force qualitatively, the second law offers a quantitative measure of the force, and the third asserts that a single isolated force does not exist. These three laws have been expressed in several ways, over nearly three centuries       

First law :	In an inertial frame of reference , an object either remains at rest or continues to move at a constant velocity , unless acted upon by a force .
Second law :	In an inertial frame of reference, the vector sum of the forces F on an object is equal to the mass m of that object multiplied by the acceleration a of the object: F = m a . (It is assumed here that the mass m is constant.
Third law :	When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.