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Homework Help: Range Equation

  1. Sep 23, 2010 #1
    1. The problem statement, all variables and given/known data
    a 78g basketball is launched at 40.4 degrees at at 14.2m, ball is released at same height as basket. what speed must the player give the ball.

    2. Relevant equations
    deltax = 2(Vo^2)sin(2theta)

    3. The attempt at a solution
    14.2 = 2Vo^2 * (.9871360) / 9.8
    69.58 = Vo^2(.9871360)
    Vo^2 = 70.48
    Vo = 8.4
  2. jcsd
  3. Sep 23, 2010 #2


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    Homework Helper

    Hi delfam,

    I don't believe this equation is quite right. What should it be?

  4. Sep 24, 2010 #3
    is it just (Vo^2) and not 2(Vo)^2
  5. Sep 24, 2010 #4


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    Gold Member

    Try solving for the general form of the range equation by taking
    [tex]x(t)=v_0\cos(\theta)t \,\,\,\,(1)[/tex] and
    [tex]y(t)=y_0+v_0\sin(\theta)t-\frac{gt^2}{2} \,\,\,\,(2)[/tex]
    solving (2) for the final time ([tex]t_f[/tex]), and then substituting [tex]t_f[/tex] into (1) and simplifying.

    Hint: your expression is missing a term from one of these equations.
    Last edited: Sep 24, 2010
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