law of motion

1

: a statement in dynamics: a body at rest remains at rest and a body in motion remains in uniform motion in a straight line unless acted upon by an external force

called also Newton's first law of motion

2

: a statement in dynamics: the acceleration of a body is directly proportional to the applied force and is in the direction of the straight line in which the force acts

called also Newton's second law of motion

3

: a statement in dynamics: for every force there is an equal and opposite force or reaction

called also Newton's third law of motion

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