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Homework Help: Are you a winner question

  1. Sep 25, 2011 #1
    1. The problem statement, all variables and given/known data

    One game at the amusement park has you push a puck up a long, frictionless ramp. You win a stuffed animal if the puck, at its highest point, comes to within 10 cm of the end of the ramp without going off. You give the puck a push, releasing it with a speed of 5.0m/s when it is 8.5m from the end of the ramp. The puck's speed after traveling 3.0m is 4.0 m/s. Are you a winner?

    2. Relevant equations

    vf^2 = vi^2 +2ad
    x(t) = 1/2at^2 + vt

    3. The attempt at a solution

    a = (vf^2-vi^2)/2d
    a = (16-25)/6
    a = -3/2 m/s/s

    x(t) = -3/2t^2 + 5t m
    v(t) = -3t + 5 m/s
    v(t) = 0 = -3t + 5
    t = 5/3

    x(5/3) = 26/5 m = 4.16m
    df = 8.5 - 4.16
    df = 4.3

    Therefore, you are not a winner because you are off by a distance of 4.2m before you earn the stuffed animal at the amusement park.

    Is this the correct method of doing this question. I feel that I am wrong because in high school it was always winning or going in the basket and not it is not. I believe it is unlikely that the answer will tell us that we are not a winner. Is there anything wrong with my logic process here?
  2. jcsd
  3. Sep 25, 2011 #2
    This is correct.

    Check your relevant equations and your previous work. You have a slight arithmetical error here that makes a very large difference in your final solution.

    Your process seems sound, just check your arithmetic. Post again if you want another double check.
  4. Sep 25, 2011 #3
    Thanks for pointing that out. I seen a two below the number and thought it was halved. It wasn't. I got it stopping 6.67cm away from the edge, and therefore I am the winner of the stuffed animal correct?
  5. Sep 25, 2011 #4
    Yes, it looks like that is correct.
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