- #1

- 220

- 6

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter rashida564
- Start date

- #1

- 220

- 6

- #2

- 31,320

- 8,104

It generally isn’t a good idea to argue with your teacher. (Especially on topics that make no difference)

Last edited:

- #3

fresh_42

Mentor

- 14,890

- 12,442

Take two, this way you always have an excuse: You can write ##E+E''=0## as ##E=E(\varphi, d\varphi)## or ##E=E(x,y)##.

- #4

- 220

- 6

So it can be considered as a motion in one dimensionTake two, this way you always have an excuse: You can write ##E+E''=0## as ##E=E(\varphi, d\varphi)## or ##E=E(x,y)##.

- #5

- 220

- 6

Both of us really love debatesIt generally isn’t a good idea to argue with your teacher. (Especially on topics that make no difference)

- #6

fresh_42

Mentor

- 14,890

- 12,442

You can choose time or angle ##\varphi##, given a fixed radius and uniform motion, which is one dimension, or you can choose position ##(x,y)## in which case you shouldn't write ##x=\cos \varphi\; , \;y=\sin \varphi##, which introduced a third variable, a parameterization, and made it rather difficult. As a differential equation, here of second degree, you can always argue, that the differentials belong to the equation, in which case you'll have even more variables: ##E=E(\varphi,d\varphi,d^2\varphi)## or ##E=E(x,y,dx,dy,d^2x,dxdy,d^2y)##.So it can be considered as a motion in one dimension

So all in all, there is nothing to add to

It generally isn’t a good idea to argue with your teacher. (Especially on topics that make no difference)

- #7

- 220

- 6

So it's all about perspectives, it can be a one dimensional motion with one variable, and it can also be with more than 3 variable in the case of differential equations.You can choose time or angle ##\varphi##, given a fixed radius and uniform motion, which is one dimension, or you can choose position ##(x,y)## in which case you shouldn't write ##x=\cos \varphi\; , \;y=\sin \varphi##, which introduced a third variable, a parameterization, and made it rather difficult. As a differential equation, here of second degree, you can always argue, that the differentials belong to the equation, in which case you'll have even more variables: ##E=E(\varphi,d\varphi,d^2\varphi)## or ##E=E(x,y,dx,dy,d^2x,dxdy,d^2y)##.

So all in all, there is nothing to add to

- #8

- 31,320

- 8,104

But in the end only one of you will be graded by the other. It is a bad idea. Furthermore, by arguing on a pointless topic you are robbing yourself from learning something that matters.Both of us really love debates

Classification of this type is completely pointless. Whether you call it 1D or 2D doesn’t change the physics. Go back to learning physics, debate is for debate club not physics class.

- #9

- 220

- 6

It's knowledgeBut in the end only one of you will be graded by the other. It is a bad idea. Furthermore, by arguing on a pointless topic you are robbing yourself from learning something that matters.

Classification of this type is completely pointless. Whether you call it 1D or 2D doesn’t change the physics. Go back to learning physics, debate is for debate club not physics class.

- #10

jbriggs444

Science Advisor

Homework Helper

- 9,811

- 4,419

I agree with @Dale. It is not knowledge. It is pointless classification. Like knowing whether a glass is half empty or half full. Just drink the thing.It's knowledge

- #11

- 31,320

- 8,104

It really isn’t.It's knowledge

You can call a handheld light a “torch” or a “flashlight”. Either way it works the same.

- #12

- 15

- 1

Cartesian coordinates, (x and y), are said to be 2-dimensional, to describe a 2-D space. Polar coordinates,

(r and theta) are also thought of as two dimensional and define a 2-D space. Of Cartesian and Polar

descriptions, Cartesian is superior. Cartesian can do one thing Polar cannot. The 2-D space spanned by

Polar Coordinates has no meaning for "r = 0." This is to say Cartesian 2-D Space does not map into

Polar 2-D Space.

- #13

Khashishi

Science Advisor

- 2,815

- 493

Both answers are right.

- #14

- 220

- 6

So it can be consider as a two dimensional motion in polar coordinatesBoth answers are right.

- #15

jbriggs444

Science Advisor

Homework Helper

- 9,811

- 4,419

It can be considered motion in a two dimensional space (the plane in which the circle is embedded) or in a one-dimensional sub-space (the circle).So it can be consider as a two dimensional motion in polar coordinates

Coordinates are irrelevant -- they just determine how you parameterize the space. The plane is still a two dimensional space whether you use cartesian coordinates, polar coordinates or something else. The circular sub-space has only one dimension no matter how you parameterize it.

Though with only one dimension, there are not a lot of choices for how to parameterize the points on a circle. About the only choices you have are origin and scaling.

- #16

- 220

- 6

can we say it's a one dimensional motion because there's only a change in theta " angular direction"

- #17

Khashishi

Science Advisor

- 2,815

- 493

- #18

jbriggs444

Science Advisor

Homework Helper

- 9,811

- 4,419

What is the space that the motion is taking place in? Is it in a circle? Is it in a plane? Is itcan we say it's a one dimensional motion because there's only a change in theta " angular direction"

Again, whether you use polar coordinates or not is irrelevant. The dimensionality of a [vector] space is invariant with respect to choice of coordinate system. It is the minimum number of elements needed in a basis for the vector space. The dimensionality of a circle, considered as a vector space of angular displacements is one. The dimensionality of a plane considered as a vector space of linear displacements is two.

- #19

fresh_42

Mentor

- 14,890

- 12,442

Both answers are right.

Thread closed.It can be considered motion in a two dimensional space (the plane in which the circle is embedded) or in a one-dimensional sub-space (the circle).

Share:

- Replies
- 5

- Views
- 607