Definition of Newton's laws of motion in US English:

Newton's laws of motion

  • Three fundamental laws of classical physics. The first states that a body continues in a state of rest or uniform motion in a straight line unless it is acted on by an external force. The second states that the rate of change of momentum of a moving body is proportional to the force acting to produce the change. The third states that if one body exerts a force on another, there is an equal and opposite force (or reaction) exerted by the second body on the first.

    • ‘Therefore, when an atom emits or absorbs a photon, its momentum changes in accordance with Newton's laws of motion.’
    • ‘When we use Newton's laws of motion to predict how a body will move, we must specify its starting position and its starting velocity as initial conditions.’
    • ‘For example, Isaac Newton's laws of motion state that a body moving through empty space with no forces acting on it will go on moving in the same way.’
    • ‘The stunt draws upon a variety of physics theories including the conservation of angular momentum and Newton's laws of motion.’
    • ‘Kepler's laws led, in turn, to Newton's laws of motion, which laid the groundwork for modern physics and cosmology.’