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Meter stick tipping over

  1. Jul 10, 2011 #1
    I've been thinking about this simple problem a lot lately and it has been bugging me.

    Let's say you have a meter stick that weighs 100g and is 1x.001x.001 meters (so it's more like a rod). You probably don't need all that information but I'll include it to be safe. The meter stick is balancing straight up so the top of the stick is a meter off the ground.

    You push the top of the meter stick just enough. So it begins to tip in one direction (let's assume you tip it in the direction of one of the sides of the stick).

    a) how long will it take the meter stick to fall if the bottom of the stick does not slide on the ground?

    b) if the coefficients of friction between the stick and the ground is .1, how long will the stick take to fall (I think it's the same as part a)? How far will the center of the stick be from where it was when it landed in part a? After the stick lands, will it slide along the ground at all? (I don't think it will)

  2. jcsd
  3. Jul 10, 2011 #2


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    hi guss! :smile:
    a) use conservation of energy

    b) find the https://www.physicsforums.com/library.php?do=view_item&itemid=73" in the a) situation … that will tell you when the stick will start to slide :wink:
    Last edited by a moderator: Apr 26, 2017
  4. Jul 10, 2011 #3
    I'm still confused, not sure where to start.
  5. Jul 11, 2011 #4


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    Has your class discussed conservation of energy yet?
  6. Jul 11, 2011 #5
    Of course. I'm just not sure how to work that into this problem. I haven't done much calculus based physics, but I've done calculus.
  7. Jul 11, 2011 #6
    You can find the time from conservation of energy?

    Is this a problem that you made up yourself?
    For the first case maybe you need to consider a bar articulated at the bottom end.
  8. Jul 11, 2011 #7
    That's what I was trying to figure out. Still not quite sure how they are going to use conservation of energy to do that

  9. Jul 11, 2011 #8
    Do you know calculus? I swear I posted something here last night, but it's gone now. If you know calculus I'll post it again. If not, I don't see how you can solve the problem.
  10. Jul 11, 2011 #9
    I know a good amount of calculus. I actually found this (from you) in my email:

    So I guess that helps a bit ;)
  11. Jul 11, 2011 #10
    Interesting. I wonder what happened to that post. I tried to edit a mistake (the line after the "From conservation of energy" has an extra 1/2 that I tried to get rid of). I guess I screwed something up editing it.
  12. Jul 11, 2011 #11


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    ngc1333, you should have received a Private Message (PM) from me about that. Did you not receive it? Please check your Private Messages.
  13. Jul 11, 2011 #12
    Got it.
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