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Homework Help: Projectile motion of a baseball

  1. Nov 16, 2007 #1
    hey, i'm having some difficulty with this problem.
    Code (Text):


      /
     /                                                            |
    [U]/ ) 45     [/U]                                                   |
        |                                                         | 3.0m
        | 1.3m                                                    |
        |[U]                                                         |             [/U]    
                                     130m
     
    this is pritty much what i have. i have no clue where to start. i've been trying to figure it out but no success... :(
     
  2. jcsd
  3. Nov 17, 2007 #2

    Shooting Star

    User Avatar
    Homework Helper

    Read up on projectile motion. Then ask any question.
     
  4. Nov 18, 2007 #3
    uh...i did...i did lyk..30 questions on projectile motion...i know how to do the questions. i'm just stuck on this question.
     
    Last edited by a moderator: Nov 23, 2007
  5. Nov 18, 2007 #4
    Were you not given a value for time between the ball being hit and it clearing the wall?

    (Although you may not need it for this question)
     
  6. Nov 18, 2007 #5
    ok...i am pretty sure i can help you witht his one :)
    if you have been learning projectile motion in class then you should know:
    [tex]\Delta Y = (V_{0}sin\varphi)(t)-.5gt^{2}[/tex]
    where [tex]\varphi = 45 degrees (the angle of "launch"[/tex]
    also you should know:
    [tex]\Delta X = (V_{0}cos\varphi)(t)[/tex]

    NOW here is what you will have to do:
    solve the change in X function for t and plug that in for wherever "t" appears in the change in Y equation
    set the change in Y to equal 1.7 m (the ball needs to at least hit that point to make it over the wall) and then solve that big nasty equation algebraically to get [tex]\ (V_{0} [/tex]

    ***edit : sorry its my first time with the math code so ill write this out
    phi = 45 cuz its the angle of launch (the writing was kinda hard to read)
    hope i was helpful!
     
    Last edited: Nov 18, 2007
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