nianfong wrote:There is a book called exactly that, man
cdobe wrote:With all due respect Fong, but you are wrong here. Vectors are abstract mathematical objects only. Forces exist in the real world. I don't think that's debatable, unless you advocate some whack idealistic philosophy.
I'm more than willing to put my statement under scrutiny...
In physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant direction, typically constrains the object to motion in a straight path. A car moving at a constant 20 kilometers per hour in a circular path does not have a constant velocity. The rate of change in velocity is acceleration. Velocity is a vector physical quantity; both magnitude and direction are required to define it. The scalar absolute value (magnitude) of velocity is speed, a quantity that is measured in metres per second (m/s or ms−1) when using the SI (metric) system.
nianfong wrote:Forces must exist, yes, but we define them mathematically as vectors. And they conform very well to that model. They go in a perfectly straight line for a certain magnitude at a given point in time. The magnitude of any force can only really be quantified mathematically. Can you look at someone pushing a car and just say "he's exerting 356.7 newtons of force on that car"? no. You have to measure how far he goes, in how much time, graph it out, and then take the derivative of the derivative. Or, you have to put a force gauge between him and the car, and guess what? that gauge will have a number on it which would be meaningless without the mathematical construct defining Force as a vector.
You are talking about physical concepts in the world, which we would not have a term for, if it were not for the "mathematical constructs" we are talking about. These concepts are BY DEFINITION, mathematical constructs.
Are you disputing that displacement is a real vector in the real world?
Bhassler wrote:cdobe wrote:With all due respect Fong, but you are wrong here. Vectors are abstract mathematical objects only. Forces exist in the real world. I don't think that's debatable, unless you advocate some whack idealistic philosophy.
I'm more than willing to put my statement under scrutiny...
In the context of communicating an idea in a non-technical, non-academic forum such as this, if vectors are easier to grasp for the general readership, what's the benefit of using the technically correct term over the intuitively understandable one? (Aside from the fact that misuse of the term happens to annoy you and possibly some others as well?) Forces (which exist in the real world) are understood with a different part of the brain than that which understands vectors (the languaging or abstraction of a force). Since the forum relies on words and not feeling, it makes sense to me to use the form of representation which is most in line with what's essentially a bunch of abstracted goo to begin with-- however, I'm open to having my mind changed on that.
Fong: maybe you otter decide whether you want to just arbitrate the definitions of things or if we want to hash it all out in the thread and then maybe clean it up and repost/re-sticky what's relevant later...
nianfong wrote:cdobe, if you don't believe me, perhaps you'll believe wikipedia's various articles on these same physics terms?
from: http://en.wikipedia.org/wiki/VelocityIn physics, velocity is speed in a given direction. Speed describes only how fast an object is moving, whereas velocity gives both the speed and direction of the object's motion. To have a constant velocity, an object must have a constant speed and motion in a constant direction. Constant direction, typically constrains the object to motion in a straight path. A car moving at a constant 20 kilometers per hour in a circular path does not have a constant velocity. The rate of change in velocity is acceleration. Velocity is a vector physical quantity; both magnitude and direction are required to define it. The scalar absolute value (magnitude) of velocity is speed, a quantity that is measured in metres per second (m/s or ms−1) when using the SI (metric) system.
http://en.wikipedia.org/wiki/Vector_(geometry)
http://en.wikipedia.org/wiki/Physical_quantity
1force noun \ˈfȯrs\
Definition of FORCE
1a (1) : strength or energy exerted or brought to bear : cause of motion or change : active power <the forces of nature> <the motivating force in her life> (2) capitalized —used with a number to indicate the strength of the wind according to the Beaufort scale <a Force 10 hurricane>
b : moral or mental strength
c : capacity to persuade or convince <the force of the argument>
2a : military strength
b (1) : a body (as of troops or ships) assigned to a military purpose (2) plural : the whole military strength (as of a nation)
c : a body of persons or things available for a particular end <a labor force> <the missile force>
d : an individual or group having the power of effective action <join forces to prevent violence> <a force in politics>
e often capitalized : police force —usually used with the
3: violence, compulsion, or constraint exerted upon or against a person or thing
4a : an agency or influence that if applied to a free body results chiefly in an acceleration of the body and sometimes in elastic deformation and other effects
b : any of the natural influences (as electromagnetism, gravity, the strong force, and the weak force) that exist especially between particles and determine the structure of the universe
5: the quality of conveying impressions intensely in writing or speech <stated the objectives with force>
In physics, a force is any influence that causes an object to undergo a change in speed, a change in direction, or a change in shape. In other words, a force is that which can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or which can cause a flexible object to deform. Force can also be described by intuitive concepts such as a push or pull. A force has both magnitude and direction, making it a vector quantity. Newton's second law, F=ma, was originally formulated in slightly different, but equivalent terms: the original version states that the net force acting upon an object is equal to the rate at which its momentum changes.[1]
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