BKK Jack said:
Inertia would not be a factor in braking, because inertia is a mass' resistance to motion. As in motionless. It is what I possess on a lazy Sunday afternoon in my recliner. Once inertia is overcome and a mass is set into motion that mass has MOMENTUM.
I only bring this up because I have seen inertia incorrectly switched for momentum several times, and it bugs me a little. Sorry for the interruption, please continue your discussion...
Wikipedia
Newton's first law: law of inertia
Lex I: Corpus omne perseverare in statu suo quiescendi vel movendi uniformiter in directum, nisi quatenus a viribus impressis cogitur statum illum mutare.
An object at rest will remain at rest unless acted upon by an external and unbalanced force . An object in motion will remain in motion unless acted upon by an external and unbalanced force.
This law is also called the
law of inertia or
Galileo's principle.
The net force on an object is the
vector sum of all the forces acting on the object. Newton's first law says that if this sum is zero, the state of motion of the object does not change. Essentially, it makes the following two points:
- An object that is not moving will not move until a net force acts upon it.
- An object that is in motion will not change velocity (including stopping) until a net force acts upon it.
The first point seems relatively obvious to most people, but the second may take some thinking through, because we have no experience in every-day life of things that keep moving forever (except celestial bodies). If one slides a hockey puck along a table, it doesn't move forever, it slows and eventually comes to a stop. But according to Newton's laws, this is because a force is acting on the hockey puck and, sure enough, there is frictional force between the table and the puck, and that frictional force is in the direction opposite the movement. It is this force which causes the object to slow to a stop. In the absence of such a force, as approximated by an air hockey table or ice rink, the puck's motion would not slow.
Although the 'Law of Inertia' is commonly attributed to Galileo,
Aristotle wrote the first known description of it:
[N]o one could say why a thing once set in motion should stop anywhere; for why should it stop
here rather than
here? So that a thing will either be at rest or must be moved
ad infinitum, unless something more powerful get in its way. [
Physics 4.8 ]
However, a key difference between Galileo's idea from Aristotle's is that Galileo realized that force acting on a body determines
acceleration, not velocity. This insight leads to Newton's First Law - no force means no acceleration, and hence the body will continue to maintain its velocity.
The Law of Inertia apparently occurred to many different natural philosophers independently. Inertia of motion was described in the third century BCE in the
Mo Tzu, a collection of Chinese philosphical texts, and the 17th century philosopher
Ren Descartes also formulated the law, although he did not perform any experiments to confirm it.
There are no perfect demonstrations of the law, as
friction usually causes a force to act on a moving body, and even in outer space gravitational forces act and cannot be shielded against, but the law serves to emphasize the elementary causes of changes in an object's state of motion:
forces.
I never said that wouldnt work. 
