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!

Vector 2B - Vector A (graphical method)

  1. Sep 15, 2008 #1
    1. The problem statement, all variables and given/known data

    Vector A is 4.00 units and 40* below x-axis. Vector B is 3.00 units and 25* below -x-axis. Use the graphical method (only ruler and protractor) to find Vector 2B - Vector A. I have to find the magnitude and direction.

    When I did it I got 8.5 and East, but I'm not sure if I did it right. When they say 4.00 and 3.00 units, is that the ax component of the vector? That's the way I did it. I drew out the vector then measured 3 and 4 units on the ax comp. of both vectors, then measured from that point down to the vector and got the ay component. Then I just solved for the magnitude.

  2. jcsd
  3. Sep 15, 2008 #2


    User Avatar
    Homework Helper

    The vector length is 4 at an angle of 40 degrees down below positive X axis and the other vector is 3 long pointing down from the negative x-axis. (The other direction of x)

    But they say 2*B which makes that vector 6 long.
  4. Sep 15, 2008 #3
    ok i just redrew it and now im lost. im getting confused about what theyre asking
  5. Sep 15, 2008 #4


    User Avatar
    Homework Helper

    You've drawn the two vectors - doubling B?

    Then reverse Vector A - same length - opposite direction.

    They say 2*B - A right. This is vector subtraction. But you do that by "adding" the negative of the Vector A.

    Now add these two vectors together.
  6. Sep 15, 2008 #5
    ok i did it again and im sure i got it wrong again but i got
    2*B-A= -.8i-.6j
    magnitude = 1
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Vector 2B - Vector A (graphical method)
  1. Graphical Analysis (Replies: 4)

  2. Graphical Methods (Replies: 2)