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Homework Help: Is this correct answer?

  1. Feb 10, 2010 #1
    This is the question:

    A baseball is hit at 30m/s at an angle of 53.0o with the horizontal. Immediately, an outfielder runs at 4.00m/s toward the infield and catches the ball at the same height it was hit. What was the original distance between the batter and the outfielder?


    1. The problem statement, all variables and given/known data
    Horizontal:
    v = 4.0m/s

    Vertical:
    a = 9.8m/s2


    2. Relevant equations
    All doing with projectile motion


    3. The attempt at a solution
    The answer I got was 107.838 meters.

    For the baseball it is:

    H = ((900sin2(53))/19.6)
    H = 29.28 m

    Vf2 = (30sin(53))2+(2*9.8*29.28)
    Vf2 = 1138.07m2/s2
    Vf = 33.88m/s

    T = (60sin53)/9.8
    T = 4.88s

    d = 30cos53*4.88
    d = 88.279m

    For the running it is:
    d = 4*4.88
    d = 19.55 m

    Dt = d1 + d2
    Dt = 88.279 + 19.55
    Dt = 107.838 m

    Therefore the total distance between them at the start was about 108 m.
     
    Last edited: Feb 10, 2010
  2. jcsd
  3. Feb 10, 2010 #2
    Yes, it's Ok. Your calculation of [itex] V_f [/itex] seems to be wrong, The ball will never go faster then 30 m/s. You're also not using it.
     
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