Before Galileo, it was believed that a force is required to keep a body moving. Later on, it was generalized to René Descartes. Galileo Galilei first formulated the law of inertia for the horizontal motion of planet Earth.

This property of a body unable to change its state is called Inertia. Newton’s third law - According to Newton's third law of motion, to every action, there is always an equal and opposite reaction. Newton’s second law - Newton's 2nd law of motion states that the rate of change of momentum of a body is directly proportional to the force applied on it, and the momentum occurs in the direction of the net applied force. Newton’s first law - Newton's first law of motion states that, if a body is in the state of rest or is moving with a constant speed in a straight line, then the body will remain in the state of rest or keep moving in the straight line, unless and until it is acted upon by an external force. Sir Isaac Newton formulated the laws of motion in the year 1686 in his book ‘Principia Mathematica Philosophiae Naturalis’. Newton's laws of motion give a scientific relationship between the forces that act on a body and the changes that occur due to this force.

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