1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Simple Vector problem agian

  1. Sep 19, 2009 #1
    The unit vector that has the same direction as the vector from the point A=(2,2) to the point B=(4,0) is?

    I chose to find the length so that would be A-B right?
    I got (-2,2) as the vector between the two points.
    I found its magnitude which was 2, then I divided the vector <-2,2> so it'll be a unit vector.

    My answer was <-1,1> but I'm wrong.
  2. jcsd
  3. Sep 19, 2009 #2
    You're pretty close

    Magnitude = sqrt(deltaX^2 + deltaX^2) <> 2

    And you want the vector going in the direction that would get you from a to b. So you want to subtract b-a to get the direction
  4. Sep 19, 2009 #3
    Ahah, Thank you

    Sometimes my mind keeps flipping numbers around and the strange thing is I repeat the same mistakes over and over its like a disease or something haha.


Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook