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Homework Help: Magnitude question

  1. Sep 28, 2009 #1
    A ball is moving through the air as shown. Its horizontal position x and vertical position y can be described by two functions: x(t) = a + b*t and y(t) = c + d*t + e*t*t.
    Here t represents time and

    a= 84 cm, b=27 cm/s, c=88 cm, d=46 cm/s and e=-490 cm/s/s.

    What is the magnitude of the initial velocity of the ball? and what is the angle between the initial velocity and the horizontal?

    Could anyone provide a much needed hint to get going on this problem?
  2. jcsd
  3. Sep 28, 2009 #2


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    Homework Helper

    Find dx/dt and dy/dt. That will give you vx and vy. Put t = 0 to get vo = sqrt(vx^2 + vy^2)
  4. Sep 29, 2009 #3
    ok i got it thanks so much!
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