A force is a push or a pull that causes an object to undergo a change in speed, direction, or shape. The use of forces is fundamental in physics and, along with some mathematical insight, Sir Isaac Newton managed to formulate three laws of motion that were first published on July 5, 1687 in his work "Philosophiæ Naturalis Principia Mathematica." These laws describe how an acting force affects the motion of a body and are actually the basis of classical mechanics.
In just a few words, the first law introduces inertia, the property of matter to resist any change in its state of motion. The second law directly connects the acceleration of a body to the acting net force, and finally the third law relates the two mutual forces of action and reaction between two bodies.
The fact that Newton's laws were not improved on for nearly three hundred years is remarkable! Newton also discovered the law of gravitation by making empirical observations. Although it has been superseded by the general relativity of Einstein, it continues to be valid when we are dealing with low mass objects.
Discover how Newton contributed to modern science by visiting the articles below: