1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    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!

Finding the Magnitude of a Diplacement Vector

  1. Dec 22, 2009 #1
    1. Cavers spelunked 2.6 km westward, 3.9 southward, and 25 meters upward. What is their displacement vector?



    2. Relevant equations



    3. The attempt at a solution - The formula for the magnitude of a vector which is

    sqrt of [(3.6)^2+(2.9)^2+(0.025)^2] ≈4.623 km
     
  2. jcsd
  3. Dec 22, 2009 #2
    Let the point P1 lie at (-2600, -3900, 25).


    Then OP1 will be a line segement whos magnitude is denoted as follows

    sqr[ (-2600)^2 + (-3900)^2 + (25)^2 ] = 4687.28m = 4.69km

    Looks about right, assuming it's 3.9km southward.

    EDIT: I failed to read the question, The displacement vector would simply be r = -2600i -3900j + 25k, where i, j, k are the unit vectors of x, y, and z.

    2nd EDIT: I reread the title and if you're looking for the magnitude of that displacement vector it is indeed 4.69km, sorry for the confusion.
     
    Last edited: Dec 22, 2009
  4. Dec 22, 2009 #3
    Alright, then I am not understanding how to find a displacement vector. I thought that the displacement of a vector was the same as its magnitude. How is finding the displacement of a vector somehow different than finding the magnitude of a vector?
     
  5. Dec 22, 2009 #4
    The displacement vector conveys both magnitude and direction. You have the distance, does the problem want direction as well?
     
  6. Dec 22, 2009 #5
    I think you are mixing up terms, its not a vector with a displacement, its a displacement vector, this is a vector that defines displacement of an object based on another parameter(usually time).
     
  7. Dec 24, 2009 #6
    You were exactly correct. That is what I was doing. Thanks for the replies everyone.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Finding the Magnitude of a Diplacement Vector
  1. Vector diplacement (Replies: 1)

Loading...