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Homework Help: What did I do wrong? Two-Dimension Vectors

  1. Oct 13, 2016 #1
    1. The problem statement, all variables and given/known data
    So the problem is:
    A woman walks 440 m at 50° S of W and then 580 m at 60° N of E. The entire trip required 15 minutes.
    A. What was the total distance (I already got the answer to this)
    B. What was the displacement of the woman?

    2. Relevant equations
    I'm almost positive I did everything right. The only two things I could think of is that I mislabeled or miscalculated the equation/triangle, or it's possible that the answer in my booklet is wrong (this has happened before since my physics teacher used online resources which don't always have the right answers.) however I want to make sure it's not just me.

    I have a quiz today based on this and the previous lesson so I need a reply quick.

    3. The attempt at a solution

    The answer in my booklet says: 165.4 m at 2.5° E of N. Is this right?

    Here is what I had written:
    http://orig05.deviantart.net/276d/f/2016/287/9/d/untitled_by_shelilla-dakysaj.jpg [Broken]
    I separated the two angles into different triangles just like we did in lessons. However since it's such a big series of equations, unless I'm a physics expert I can't tell just by looking if I did something wrong, and if I try to revise it there is so many things that can change the answer so it's too confusing to try.
    Last edited by a moderator: May 8, 2017
  2. jcsd
  3. Oct 13, 2016 #2


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    Staff: Mentor

    You've used the Ay component in your calculation of x and Ax in your calculation of y. X directions should be east or west, and Y directions north or south.
  4. Oct 13, 2016 #3


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    Science Advisor
    Homework Helper
    2017 Award

    Booklet is right....
    What does 60 degrees north of East mean ?

    [edit] Gn is right; I was wrong-footed by your drawing; the numbers are OK.
  5. Oct 13, 2016 #4
    Crap, you're right. I probably shouldn't have started this assignment at 9, I made a few mistakes in other questions (such as sin-1(# + #) instead of sin-1(#/#) ) lol, thanks for pointing that out!
  6. Oct 13, 2016 #5


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    Staff: Mentor

    Glad to help. Good luck with your studies!
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