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Homework Help: Middle of a Frozen Lake!

  1. Mar 6, 2005 #1
    I have this question I have to do for my physics class... I have been thinking about it for an hour now, but can't figure it out. Any help would be greatly appreciated. here is the question:

    You find yourself in the middle of a frozen lake with a slippery surface so slippery (ms = 0, mk = 0) that you cannot walk. However, you happen to have several rocks in your pocket. The ice is extremely hard. It cannot be chipped. The rocks slip on the ice as much (if not better) than your feet do. Can you think of a way to get to the shore? Use free body diagrams and Newton's laws to explain your reasoning.
  2. jcsd
  3. Mar 6, 2005 #2
    this may be erroneous but here goes anyway

    couldnt you simply throw the rocks in the opposite direction of the shore

    This way because of conservation of momentum you will get pushed forward. I guess you should throw them all at once that way you get max acceleration. Otherwise the momentum mayb e not be enough to make you move. You wont slow down becuase there is no firciton.
  4. Mar 6, 2005 #3
    I was kind of thinking about something like that, but I don't know if I can use it because we have not studied the conservation of momentum yet. If I did do that, how would I draw the free body diagram? Thanks.
  5. Mar 6, 2005 #4
    thats the best solution. That is newtons 3'd law. When you throw the rock in the opposite direction, there is an equal and opposite force on you. Now just put the diagram together.


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