Graphics Reference
In-Depth Information
At even higher speeds the cannonball will escape the earth's gravitational pull
and will not fall back to earth nor be held in orbit around the earth; instead
it will continue on its way and move away from the earth into space. It will
continue in this manner until it encounters another object or the gravitational
forces of another object, which will either stop it or deflect it.
Newtononian Laws of Motion
It is mostly very evident to the observer that animals and other animate
beings have the ability to exert forces from within to create a whole range
of movements that they have, for the most part, complete control over. They
swim, they run, they jump, and they eat. There are many other things that we
see around us that move, some of them in very dynamic ways that require
external forces to create this dynamic motion: air pressure and wind create
the waves on the ocean, tidal forces are responsible for moving vast quantities
of material around, the flowing water in rivers is due to geographical and
geological conditions—even the movement of clouds, the blowing of leaves
on the trees, and the violent eruptions of volcanoes all are determined by a
variety of external forces.
These laws describe the relationship between the forces acting on a body and
the motion of that body. They are physical laws that form the basis for classical
mechanics and are used to describe the motion of larger objects, whereas the
motion of subatomic objects and material is described in terms of quantum
mechanics. The laws that underpin classical mechanics are capable of
producing highly accurate and predictable results; it is on this predictability
that our engineering and technology are built and that provides us with a
basis for our analysis of movement.
Newton outlined the laws of motion that, along with his work on universal
gravitation, explained the findings of the German astronomer and mathematician
Johannes Kepler with regard to Kepler's work on the motion of planets. Newton
went on to use these laws to investigate the motion of many other subjects.
Newton asserted that all forces should not be seen as remote and divorced
from objects and that any given force is dependent on the interactions
between objects. As a result, there can be no unidirectional forces; they are all
determined by the location of objects and their relationships to one another,
as we shall see when we cover Newton's third law of motion.
Newton's three laws can be outlined as follows:
First law.
An object will remain at rest until a force acts on it.
Second law.
An object will accelerate proportionately to the force applied to it.
Third law.
For every action there is an opposite and equal reaction.
There should be no need for us to get bogged down with any formulas that
fully explain these laws, but I think by adding a
little
more detail we would
gain some benefit. So let's do that.
