# Position Vectors

1. Dec 9, 2015

### Erkan Tur

1. The problem statement, all variables and given/known data

2. Relevant equations
Relevant equations can be derived from the formulas, by exchanging x to v, v to a, etc.

3. The attempt at a solution
I've tried to graph them, but I am not able to visualize or understand them.

If you can suggest me some parts or questions relevant to this topic, I will be so happy because I cannot understand this concept.

2. Dec 9, 2015

### Joydeep Munshi

Hi,

the info given in qn is not correct. here angle theta cannot be between r and z axis. as in that case theta becomes 90 degree and that doesn't make sense. theta is between r vector and x-axis and in that case it is just a transformation between rectangular and polar coordinates in 2-D. Please check attachment for your help. I guess you can try qn. c and qn. d now
.

3. Dec 9, 2015

### Erkan Tur

Hello,
I was looking for it also, thank you for your kind reply and your work, I am trying to visualize the angle for the z axis, since there is no component for the z hat plane, it doesn't make sense thus it is 90 degrees. I agree with you, neverthless I told them this morning, but he told that there is more to think about that point. Thank you for your help, I understood your kind help correctly. Do you have any books in your mind, about the part of this classical mechanics?

4. Dec 9, 2015

### Erkan Tur

But if we neglect that z part and exchange with x hat, it is reasonable. Thank you anyway kind friend, I will be solving it as x

5. Dec 12, 2015

### Joydeep Munshi

Hi,

See if the angle is between Z axis and r vector than definitely r hat becomes y hat and theta hat becomes (-ve) x hat. from that perspective it is a rotation of the vector by 90 deg if you transform from rectangular to the r-theta co-ordinate.

You can follow Spiegel for concepts on Vectors and Curvilinear co ordinates.