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Homework Help: Freefall, is the answer really 20 ?

  1. Sep 30, 2007 #1
    1. The problem statement, all variables and given/known data

    A lead ball is dropped into a lake from a diving board 5.0 m above the water. After entering into the water it sinks into the bottom with a constant velocity which it hit the water for 3 seconds. and hits the bottom of the lake. How deep is the late ?

    2. Relevant equations
    Vf ² - Vi ² = 2as

    3. The attempt at a solution

    Well I just used this equation and I get a velocity of 9.89 which I find odd. I think it should take less then 1 second to hit the water.

    I get an answer of 29 meters by finding out the velocity and multipling by 3 seconds.
    Altho in the answers it says 20.
  2. jcsd
  3. Oct 1, 2007 #2
    You should be right. It didn't say 2 seconds?
  4. Oct 1, 2007 #3


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    Homework Helper

    did you post the question exactly? Is the 3 seconds after it hits the water? I'm confused by this part:

    "which it hit the water for 3 seconds. and hits the bottom of the lake"
  5. Oct 1, 2007 #4
    show more steps, i don't like the equation you used
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