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Homework Help: Kinematics Problem

  1. Sep 11, 2004 #1
    In diving to a depth of 635 m, an elephant seal also moves 590 m due east of his starting point. What is the magnitude of the seal's displacement?

    Would I just take the 590m and subtract if from 635m to get the answer?

    Is the answer 45m?
  2. jcsd
  3. Sep 11, 2004 #2


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  4. Sep 11, 2004 #3
    Use vector addition for these types of problems. Find vectors for the two separate displacements and add them vectorally.
  5. Sep 11, 2004 #4


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    Yep, Pythagoras!
  6. Sep 11, 2004 #5
    would I do this?

    Take the Square root of 635^2 + 590^2 to get the answer?
  7. Sep 11, 2004 #6

    dont take my word for it(im not good at physics, lol), but this is how i think your suppose to do it:

    x=590 (east)
    y=-635 (south, cause it's diving and negative because it's south)

    mag is just a^2+b^2=c^2
    so... 590^2 + (-635)^2 = c^2

    and direction is... arctan(y/x) = arctan (-635/590)

    im trying to do as many physics problems as i can and reading over my notes agian this weekend(got a test this monday)

    can anyone tell me if my work is correct?
    Last edited: Sep 11, 2004
  8. Sep 11, 2004 #7
    That's okay but to be sure I'd follow Sirus's advice about vectors (read below).
    Last edited: Sep 11, 2004
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