The product of a vector and the length of a polar coordinate

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Homework Help Overview

The discussion revolves around the multiplication of a vector and the square of a polar coordinate length, specifically focusing on the expression A*R^2, where A is defined in terms of vector components and R is related to the Euclidean distance in three-dimensional space.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants are attempting to clarify the multiplication of a vector by a scalar and are questioning the notation used for vectors and scalars. There is uncertainty about the definitions of R and A, as well as the notation for unit vectors.

Discussion Status

Some participants have provided clarifications regarding the definitions of R and A, while others are exploring the implications of multiplying vectors by scalars. The discussion is ongoing, with multiple interpretations being considered.

Contextual Notes

There is a lack of clarity regarding the notation and definitions used in the problem, particularly concerning the representation of vectors and the meaning of R. Participants are encouraged to define their terms more clearly to facilitate understanding.

catsonmars
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Homework Statement


So I am not sure how to multiply these two (A*R^2) together.


Homework Equations


A=( x^2 + y^2 + z^2 ) (xe + y e + z e )
Where x represents the three vector compones

I also have R^2=x^2+y^2+z^2

The Attempt at a Solution



Is the product of A (x^3e + y^3 e + z^3 e )? If so why is that? I would think because of some vector rule I am not sure of.
 
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catsonmars said:

Homework Statement


So I am not sure how to multiply these two (A*R^2) together.


Homework Equations


A=( x^2 + y^2 + z^2 ) (xe + y e + z e )
Where x represents the three vector compones

I also have R^2=x^2+y^2+z^2

The Attempt at a Solution



Is the product of A (x^3e + y^3 e + z^3 e )? If so why is that? I would think because of some vector rule I am not sure of.

You haven't told us what R is. Also, (xe + y e + z e ) is strange notation. Is e the base of natural logarithms? Or is that supposed to represent a vector ##\langle x,y,z\rangle## and is that ##\vec R##? Is ##R^2## supposed to represent ##\vec R \cdot \vec R##? It would help greatly if you would define your terms and use standard notation.
 
R is just (x^2+y^2+z^2)^1/2 and it isn't a vector.

Let me rewrite A
A=( x^2 + y^2 + z^2 ) (x[itex]\hat{x}[/itex] + y[itex]\hat{y}[/itex] + z[itex]\hat{z}[/itex] )
 
catsonmars said:
R is just (x^2+y^2+z^2)^1/2 and it isn't a vector.

Let me rewrite A
A=( x^2 + y^2 + z^2 ) (x[itex]\hat{x}[/itex] + y[itex]\hat{y}[/itex] + z[itex]\hat{z}[/itex] )
x2 + y2 + z2 is just a scalar. What happens when you multiply a vector by a scalar?

Also, are ##\hat{x}##, ##\hat{y}##, and ##\hat{z}## some random unit vectors? If they are unit vectors in the directions of the x, y, and z axes, they are usually written i, j, and k.
 

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