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Homework Help: How deep is the well

  1. Feb 4, 2009 #1
    1. The problem statement, all variables and given/known data

    How deep is the well remember its takes him 3.8 seconds to hear the stone hit the bottom not 3.8 to see it hit the bottom.
    u=0ms^-1
    a=10ms^-2


    2. Relevant equations

    Not 100% sure what equations to use becuase my teacher goes to quickly

    3. The attempt at a solution

    Would you be able to show me the equations to use to solve it.
    Thanks Nick.
     
  2. jcsd
  3. Feb 4, 2009 #2
    Try these

    Depth = InitialSpeed*DropTime + 0.5*Acceleration*DropTime²

    SpeedOfSound = Depth/EchoTime

    TotalTime = DropTime + EchoTime
     
  4. Feb 4, 2009 #3
    Thanks mate, I got 35.28m for the depth of the well, is that correct??
     
  5. Feb 4, 2009 #4
    Dunno mate! I didn't get that far.
     
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