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Homework Help: Ball thrown vertically upward

  1. May 2, 2010 #1
    1. The problem statement, all variables and given/known data
    A boy throws a ball vertically upward from the ground with the velocity 25 m/s. On its way down it is caught 5 m above the ground. How long did the trip take and with what velocity was it coming down?


    2. Relevant equations



    3. The attempt at a solution
    Which equation of motion should I use? Please give me hints
     
  2. jcsd
  3. May 2, 2010 #2

    rl.bhat

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    Homework Helper

    Use
    y = Vi*t - 1/2*g*t^2.
    Solve the quadratic to find t. You will get two values. For return journey, take the larger value of t.
     
  4. May 2, 2010 #3
    What do you mean by solve the quadratic for t?
     
  5. May 2, 2010 #4

    rl.bhat

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    Homework Helper

    In the problem y is given. g is known. Initial velocity is given. Substitute these values in the kinematic equation and solve for t.
     
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