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Homework Help: Vector prblem, HELP ME

  1. Jul 8, 2004 #1
    A jogger travels a route that has two parts. The first is a displacement A of 2.50 km due south, and the second involoves a displacement B that points due east. (a) The resultant displacement A+B has a magnitude of 3.75 km. What is the magnitude of B, and what is the direction of A+B relative to due south? (b) suppose that A-B had a magnitude of 3.75 km. What then would be the magnitude of B, and what is the direction of A-B realtive to due south?
    :uhh:

    I have an answer for this problem I just want to know if it is right.
    (a)The magnitude of B is 2.80 km
    A+B points 48.188 degrees East of South

    (b)the magnitude of B is 2.80 km
    A-B points 48.188 degrees West of South
     
    Last edited: Jul 8, 2004
  2. jcsd
  3. Jul 8, 2004 #2

    AKG

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    Looks pretty good. In finding the direction, I got the angle to be 48.190. Make sure you're not using rounded values, in fact you can just use cosX = 2.50/3.75, and solve for X (which is what I did). However, you should round to 3 significant digits, giving you 48.2 anyways, which would be the same using my number or yours.
     
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