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Homework Help: Projectile Motion question

  1. Sep 16, 2008 #1
    1. The problem statement, all variables and given/known data
    Well to sum up the question: a football kicker kicks a ball with 20m/s initial velocity with a 53 degree angle. the goal post is 36m away and is 3.05m tall. does the ball pass the goal post? does the ball approach the crossbar while still rising or falling?

    acceleration= -9.8 m/s/s
    V initial = 20m/s
    angle theta= 53 degrees
    height of post=3.05m

    2. Relevant equations
    range= (velocity initial x) multiply (time)
    vix (velocity initial x) = vi cos angle theta
    viy (velocity initial y) = vi sin angle theta

    y=(viy) multiply (time) + 0.5at^2

    3. The attempt at a solution

    using the above information i found the that the ball crosses the goal post by 0.85meters.

    here the problem. i dont know how to do the second part. any and all help will be appreciated thx.
  2. jcsd
  3. Sep 17, 2008 #2


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    Homework Helper

    You could find out at what range the maximum height occurs. Is this before or after the goal post?
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