Finding a Unit Vector Along $\vec{A}$ - Please Help!

In summary, the conversation discusses finding a unit vector along the direction of a cylindrical vector and whether the same method can be applied for spherical coordinates. The expert explains that for cylindrical coordinates, the length of the vector does not change and the same method can be used. However, it is not clear if the same applies for spherical coordinates and further discussion is needed on whether spherical coordinates form an orthonormal system.
  • #1
Drain Brain
144
0
Hello! I need help with this problem

how do you find a unit vector along the direction $\vec{A}=2\hat{a_{\rho}}-z\hat{a_{z}}$(cylindrical)?

do I have to convert it to Cartesian or there is a direct method? please help! Thanks!
 
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  • #2
The vector itself is responsible for the direction. All you need to do is divide the vector by its magnitude:

$$\vec{u} = \frac{\vec{A}}{\| \vec{A}\|} = \frac{2 \vec{a}_{\rho} - z \vec{a}_z}{\sqrt{4+z^2}}.$$
 
  • #3
Fantini said:
The vector itself is responsible for the direction. All you need to do is divide the vector by its magnitude:

$$\vec{u} = \frac{\vec{A}}{\| \vec{A}\|} = \frac{2 \vec{a}_{\rho} - z \vec{a}_z}{\sqrt{4+z^2}}.$$
HI fantini
$\vec{A}=2\hat{a_{\rho}}-z\hat{a_{z}}$ <--- this vector is in cylindrical form. Why did you directly get the unit vector from a cylindrical form? Is that valid?
 
  • #4
Yes, it is valid. This is because cylindrical coordinates form an ortonormal system. Thus the length of the vector does not change from cartesian. You can compute the length as you would normally. :)
 
  • #5
Fantini said:
Yes, it is valid. This is because cylindrical coordinates form an ortonormal system. Thus the length of the vector does not change from cartesian. You can compute the length as you would normally. :)

does this also holds for spherical form?
 
  • #6
Drain Brain said:
does this also holds for spherical form?

Can you prove if spherical co-ordinates form an orthonormal system?
 

Related to Finding a Unit Vector Along $\vec{A}$ - Please Help!

1. What is a unit vector and why is it important in finding a unit vector along $\vec{A}$?

A unit vector is a vector that has a magnitude of 1 and points in a specific direction. In finding a unit vector along $\vec{A}$, it is important because it helps to normalize the given vector, making calculations easier and providing important information about the direction of the vector.

2. How do you find the unit vector along $\vec{A}$?

To find the unit vector along $\vec{A}$, you first need to calculate the magnitude of $\vec{A}$. Then, divide $\vec{A}$ by its magnitude to get the unit vector. The formula is $\vec{A}_{unit} = \frac{\vec{A}}{|\vec{A}|}$.

3. Can a unit vector have a negative magnitude?

No, a unit vector always has a magnitude of 1, which is a positive number. This is because the purpose of a unit vector is to represent direction, not magnitude.

4. How is a unit vector different from a normal vector?

A unit vector has a magnitude of 1 and represents only direction, while a normal vector can have any magnitude and represents both magnitude and direction.

5. Why do we use unit vectors in mathematics and science?

Unit vectors are commonly used in mathematics and science because they simplify calculations and provide important information about the direction of a vector. They also allow for easier comparison and manipulation of vectors in equations and formulas.

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