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Homework Help: Physics Riding a loop-the-loop?

  1. Oct 19, 2011 #1
    1. The problem statement, all variables and given/known data

    A car in an amusement park ride rolls without friction around the track it starts from rest at a point A from height H above the bottom of the loop. treat the car as a particle. what is the minimum value of height (in terms of R radius)such that the car doesn't fall off the very top of the ramp.

    2. Relevant equations

    E=mgh
    gravity constant
    Fc=.5mv^2
    K=.5mv^2

    3. The attempt at a solution

    i dont really know where to start but ill give it a shot.
    2R is the height of the

    so mgh-mg2R= 1/2mv^2


    i dont really know what else to do -_-

    since mgh-mg2R=1/2mv^2 could you assume that v approaches 0 then mgh=mg2R which makes sense to me because if the surface is frictionless then energy is being conserved so does this mean if the height from which it came = the height of what it needed to go to?
     
  2. jcsd
  3. Oct 20, 2011 #2

    PeterO

    User Avatar
    Homework Helper

    You don't want to merely get the cart back up to the top of the loop-the-loop, you want it to stay on the track, so it has to have a specific speed [at least] so the hill will need to be higher. How much higher is the question.
     
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