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Re: [Phys-L] fundamental notion of force --> using an arrow to represent something more than a vector



diferent physical systems have diferent vector spaces usefull to model them


forces in a unique mass center are vectors in a particular vector space.
Same class but different space in one mass than in another one.

forces in a multiple rigid bodies setup have another kind of vector space.

fluid mechanics other kind. Tangent spaces ....

quantum mech ...

etc..



2015-10-23 23:27 GMT-03:00 Diego Saravia <dsa@unsa.edu.ar>:

So you can not define an individual vector

you must define a set, the vector space. all its members are vectors

in that set a sum of two vectors MUST be a vector for example.



wikipedia

A *vector space* (also called a *linear space*) is a collection of
objects called *vectors*, which may be added
<https://en.wikipedia.org/wiki/Vector_addition> together and multiplied
<https://en.wikipedia.org/wiki/Scalar_multiplication> ("scaled") by
numbers, called *scalars
<https://en.wikipedia.org/wiki/Scalar_(mathematics)>* in this context.
Scalars are often taken to be real numbers
<https://en.wikipedia.org/wiki/Real_number>, but there are also vector
spaces with scalar multiplication by complex numbers
<https://en.wikipedia.org/wiki/Complex_number>, rational numbers
<https://en.wikipedia.org/wiki/Rational_number>, or generally any field
<https://en.wikipedia.org/wiki/Field_(mathematics)>. The operations of
vector addition and scalar multiplication must satisfy certain
requirements, called *axioms <https://en.wikipedia.org/wiki/Axiom>*,
listed below <https://en.wikipedia.org/wiki/Vector_space#Definition>.

*Axiom**Meaning*Associativity
<https://en.wikipedia.org/wiki/Associativity> of addition*u* + (*v* + *w*)
= (*u* + *v*) + *w*Commutativity
<https://en.wikipedia.org/wiki/Commutativity> of addition*u* + *v* = *v*
+ *u*Identity element <https://en.wikipedia.org/wiki/Identity_element> of
additionThere exists an element *0* ∈ *V*, called the *zero vector
<https://en.wikipedia.org/wiki/Zero_vector>*, such that *v* + *0* = *v* for
all *v* ∈ *V*.Inverse elements
<https://en.wikipedia.org/wiki/Inverse_element> of additionFor every *v* ∈
V, there exists an element −*v* ∈ *V*, called the *additive inverse
<https://en.wikipedia.org/wiki/Additive_inverse>* of *v*, such that *v* +
(−*v*) = *0*.Compatibility
<https://en.wikipedia.org/wiki/Semigroup_action> of scalar multiplication
with field multiplication*a*(*b**v*) = (*ab*)*v* [nb 2]
<https://en.wikipedia.org/wiki/Vector_space#cite_note-3>Identity element
of scalar multiplication1*v* = *v*, where 1 denotes the multiplicative
identity <https://en.wikipedia.org/wiki/Multiplicative_identity> in *F*.
Distributivity <https://en.wikipedia.org/wiki/Distributivity> of scalar
multiplication with respect to vector addition *a*(*u* + *v*) = *a**u* +
*a**v*Distributivity of scalar multiplication with respect to field
addition(*a* + *b*)*v* = *a**v* + *b**v*



2015-10-23 23:18 GMT-03:00 Diego Saravia <dsa@unsa.edu.ar>:



2015-10-23 19:32 GMT-03:00 John Denker <jsd@av8n.com>:

On 10/23/2015 03:14 PM, Jeffrey Schnick wrote:

Sometimes a force can be represented by a vector.


a vector is a vector in a specific vector space

different lines of actions are diferent vector spaces in some cases

differents points of applications in other cases

or all the pysical space in others

perhaps these is usefull

https://en.wikipedia.org/wiki/Affine_space




--
Diego Saravia
Diego.Saravia@gmail.com
NO FUNCIONA->dsa@unsa.edu.ar

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--
Diego Saravia
Diego.Saravia@gmail.com
NO FUNCIONA->dsa@unsa.edu.ar

====================================================================
"Disclaimer:" Haré lo que desee con los correos que reciba, quien no este
de acuerdo, que se abstenga de enviarme correo a mí o a las listas donde
este suscripto.
En particular NO VALE ningun "disclaimer" que indique que el correo enviado
es privado o sujeto a normas de empresas, gobiernos, u organizaciones de
cualquier tipo.
Con relación a los estados y sus leyes, analizare cualquier norma aplicable
en el territorio donde eventualmente actúe en el momento, escucho a
cualquiera que tenga algo que decir.
Con respecto en particular a los derechos de autor, salvo acuerdo previo,
gozaré plenamente de las 4 libertades con todo lo que reciba,
considerandolo, en cuanto a lo patrimonial,
como propio.
====================================================================