Register to reply 
Position and Position vector 
Share this thread: 
#1
Oct513, 10:55 AM

PF Gold
P: 41

What is a position vector? Is their any difference between the position vector and position? Isnt position of a point supposed to represent its direction in Cartesian plane as well(Positive quadrants , negative quadrants). So why two different terms?



#2
Oct513, 12:29 PM

PF Gold
P: 6,294

Just at a guess, I'd say it's like this: position in a 2D Cartesian coordinate system is absolute and is described by two numbers. A position vector is relative to some starting point, which MIGHT be the origin but might not be.



#3
Oct513, 01:12 PM

Sci Advisor
HW Helper
PF Gold
P: 3,288

One might say that a position vector ##[x\,\,y]## is the equivalence class of pairs of points ##(a,b)##, ##(c,d)## in the plane satisfying ##ca = x## and ##db = y##.



#4
Oct513, 03:48 PM

Sci Advisor
P: 6,059

Position and Position vector
Position vector in a plane: vector from (0,0) to (x,y) 


#5
Oct613, 01:07 AM

PF Gold
P: 41

Edit#2 : Thanks. Your answers were right i guess. 


#6
Oct613, 09:11 AM

Math
Emeritus
Sci Advisor
Thanks
PF Gold
P: 39,503

Personally, I don't like the very concept of a "position vector" it only makes sense in Euclidean space. When I was young and foolish (I'm not young any more) I worried a great deal about what a "position vector" looked like on a sphere. Did it "curve" around the surface of the sphere or did it go through the sphere? The answer, of course, is that the only true vectors are tangent vectors that lie in the tangent plane to the surface at each point.



#7
Oct613, 11:31 AM

PF Gold
P: 41




#8
Oct713, 01:07 AM

P: 72

A position vector is a vector in Euclidean space that points from the origin to your location



#9
Oct1013, 06:04 PM

P: 3

I would say that the biggest difference is that a position vector assumes you are working in a space with numbers (like a Vector Space) and a position may not.
If you are studying Euclidean Geometry, based on the Elements, there are no numbers (at least for many books there is no need of numbers). So a position might be described as the intersection of two lines, or the center of a circle. In this case, there is no position vector, only a position. You are working in a Euclidean space that does not have the usual Vector Space information available. 


Register to reply 
Related Discussions  
Position vector perpendicular to tangent vector yields a sphere  Calculus & Beyond Homework  1  
Is the Sun’s position in the Galaxy close to its predecessor’s position?  Astronomy & Astrophysics  4  
Amount of work that is done to adjust the capacitor from position A to position B  Introductory Physics Homework  2  
Difference between the average position and the most likely position of a particle  Advanced Physics Homework  91  
Deriving Vector and position vectors from Force vector  Introductory Physics Homework  3 