Quick question on vectors in polar coordinates

In summary, polar coordinates can be used to represent vectors and their direction and magnitude, but it does not necessarily mean that a vector represents rotational force. Different coordinates can be used to solve different problems and polar coordinates may be preferred in cases where it simplifies the math. Vectors can have both radial and angular components, but they do not always represent forces.
  • #1
schlynn
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This is more of a general question, really no math involved. Since polar coordinates are, (theta, r), the direction of the vector is theta, and the magnitude is r, in polar coordinates, does a vector represent rotational force?
 
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  • #2
Hi there,

No necessiraly. Different coordinates will be used to solve different problems. But every coordinate can be used to solve every problem.

Let me explain a bit more, it might get clearer. You and I know that some equations in the square coor (x,y,z) become very complicated, specially in cases where the vector is not linear, but following some curvature. Therefore, the polar coor will be preferred in cases where it simplifies the math.

To give you a simple example, take a vector of radius r=1, which remains fix. The vector direction varies over time. Therefore, if you would have to write equation in (x,y,z) to explain it's behaviour in time, you would have (x,y,z) that varies all the time. Which in a polar coor you only have [tex]\theta[/tex] that varies.

Hope this makes it clear enough? Cheers
 
  • #3
schlynn said:
This is more of a general question, really no math involved. Since polar coordinates are, (theta, r), the direction of the vector is theta, and the magnitude is r, in polar coordinates, does a vector represent rotational force?
It is actually most common t represent vectors, even in polar coordinates, with x and y components, but yes, you can have "radial" and "angular" components. Writing vectors as [itex]\left< r, \theta\right>[/itex], a vector with 0 radial component would represent a "rotation". Of course, vectors don't necessarily represent forces.
 

1. What are polar coordinates?

Polar coordinates are a system of representing points in a plane using a distance from the origin (called the radius) and an angle from a fixed reference line (called the polar axis).

2. How do you convert a vector from Cartesian coordinates to polar coordinates?

To convert a vector from Cartesian coordinates (x,y) to polar coordinates (r,θ), you can use the formulas r = √(x²+y²) and θ = tan⁻¹(y/x).

3. What is the difference between a polar vector and a Cartesian vector?

A polar vector has a magnitude and direction described by its radius and angle, while a Cartesian vector has a magnitude and direction described by its x and y components.

4. Can polar coordinates be used in three-dimensional space?

Yes, polar coordinates can be extended to three-dimensional space by adding a third coordinate (called the height or altitude) and using a third angle (called the azimuth angle) to represent the direction.

5. How are vector operations (such as addition and subtraction) performed in polar coordinates?

In polar coordinates, vector operations can be performed by converting the vectors to Cartesian coordinates, performing the operation, and then converting the result back to polar coordinates. Alternatively, vector operations can be performed directly using the polar coordinates and trigonometric functions.

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