1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook