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Homework Help: Found half an answer, I need help with the direction please.

  1. Feb 6, 2012 #1
    1. The problem statement, all variables and given/known data

    A projectile is launched with a horizontal velocity of 10 m/s and a vertical velocity of 20 m/s. What is the magnitude and direction of the projectile’s initial velocity?

    3. The attempt at a solution

    I've tried using the trigonometric method but I end up with only 1 side and 1 angle which isn't good. I could logically think that since one side is 20 and one side is 10, the angle would be

    90 / 3 = 30

    30 * 2 = 60

    But the answer sheet says 63 degrees. :"(

    I found the magnitude but the problem is I can't find the direction. More specifically, at what degree is it travelling at.

    The magnitude is 22.

    So it should be

    22 m/s [Up x Horizontal]

    x = an unknown angle

    I'm having trouble finding the value of x.

    Than you. :3

    Last edited: Feb 6, 2012
  2. jcsd
  3. Feb 6, 2012 #2


    User Avatar
    Homework Helper

    Have you drawn a picture?
    If you did you would see a right-angled triangle, and just use the Tangent function.
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