Mechanics 2: Linear and Rotational Dynamics - 3D Math Primer for Graphics and Game Development - page 554

12.1 Newton's Three Laws

Sir Isaac Newton established three simple laws that provide a framework,
commonly known as Newtonian mechanics, for understanding such diverse
physical systems as an apple falling from a tree, the motion of the planets,
and the physical interactions that happen in a video game. Newtonian
mechanics is also called classical mechanics, and that name should alert
you to the fact that the laws we are about to study are wrong, in the
sense that they do not agree with the result of experiments conducted at
very high speed (which require relativistic mechanics) or at very small scale
(which require quantum mechanics). 1 For everyday phenomena (and for the
phenomena we need to simulate in a video game), the discrepancy between
the results predicted by Newtonian mechanics and the correct results (as
correctly predicted by quantum-relativistic mechanics) is generally less than
can be detected with the most accurate instruments. The differences in the
predictions become significant only at speeds very close to the speed of light
and at scales approaching the size of an atom; otherwise, all the theories
are in great agreement with each other and with experimental results. It
was precisely because Newtonian mechanics has such a long and decorated
history of accurate predictions that it was so shocking to find out that the
laws were in need of correction. It should be clear that these laws, having
been su cient to describe the motions of the heavenly bodies to a great
deal of accuracy, will also be quite su cient for our purposes here.

12.1.1 Newton's First Two Laws: Force and Mass
Chapter 11 noted that mass measures the degree to which an object re-
sists being accelerated. This resistance is called inertia, and the physical
quantity needed to overcome it and create an acceleration is called force.
In other words, all of those “causes of motion” that we so scrupulously
avoided mentioning in the previous chapter actually go by the collective
name force.
The idea that objects resist acceleration is summarized by Newton's
first law.

Newton's First Law

Every body persists in its state of being at rest or of moving uniformly
straight forward, except insofar as it is compelled to change its state by
force impressed.

1 Some of these experiments took place in the imaginations of physicists.