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Homework Help: Dot product

  1. Apr 5, 2008 #1
    1. The problem statement, all variables and given/known data
    Vector A has a magnitude of 5.00 units, and vector B has a magnitude of 9.00 units. The two vectors make an angle of 49° with each other. Find (vector A)(vector B)

    2. Relevant equations

    3. The attempt at a solution


    square root (5^2+0^2)

    Could someone please tell me if this is correct and if not could someone show me how to do it?

    Thank you very much
  2. jcsd
  3. Apr 5, 2008 #2

    Shooting Star

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    Homework Helper

    (vector A)(vector B)?

    This notation does not mean anything. Possibly, you mean the scalar product A.B?

    How did you utilize the 49 deg given in the problem?

    A.B = (magnitude A)(magnitude B)cos [itex]\theta[/itex], where [itex]\theta[/itex] is the angle between A and B.

    Take my advice given in the other post.
  4. Apr 6, 2008 #3
    Thank you

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