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A stone is dropped from a window 5m high what is its speed

  1. Nov 28, 2007 #1
    Ok this might be a simple problem but i have no idea how to do it;

    A stone is dropped from a window 5m high what is its speed when it hits the ground.

    I dont need answer i just need a formula or some guidence
    Thanks
     
    Last edited by a moderator: Mar 7, 2013
  2. jcsd
  3. Nov 28, 2007 #2

    rock.freak667

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    What does the stone have at 5m high?(what kind of energy) when dropped...this kind of energy is converted into energy a body possesses by virtue of its motion...

    Law of conservation of energy
     
  4. Nov 28, 2007 #3
    at 5m it has gravitaitional potential energy and when its is dropped it is converted to kinetic energy
    ive got the formula for GPE it is height x weight
    and for kinetic energy its 1/2 x mass x speed^2

    these might not be the right formulas as i dont have the mass
     
  5. Nov 28, 2007 #4

    rock.freak667

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    But...weight= mass x accel. due to gravity...so if you equate the two you will get:
    1/2 x mass x speed^2= Height x weight

    1/2 x mass x speed^2=Height x mass x accel. due to gravity


    do you see anything canceling out?
     
  6. Nov 28, 2007 #5
    amny thanks
    i appreciate your help
     
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