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BASIC gravity problem

  1. Apr 11, 2009 #1

    TG3

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    I feel like an idiot asking this, it's review of a previous course as we start a new quarter, and I KNOW I used to be able to do this.... but I don't remember how too. Time to review...

    1. The problem statement, all variables and given/known data

    A tomato is dropped from 100 feet above the ground. At what speed does it hit the ground?
    How long does it take to fall the last 100 feet?

    2. Relevant equations

    Acceleration due to gravity is 32 ft/sec^2

    3. The attempt at a solution

    If I recall correctly, delta X = 1/2 at^2
    100 = 1/2 32 T^2
    200 = 32 T^2
    6.25 = T^2
    T = 2.5
    Tomato hits ground after 2.5 seconds.
    So now, plugging that in:
    32 (2.5)^2 = 200... which is definitely not right.
     
  2. jcsd
  3. Apr 11, 2009 #2

    LowlyPion

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    Homework Helper

    Doing it your way, the last step would be V = a*t not t2

    Otherwise you could take the Potential energy to kinetic energy relationship:

    m*g*h = 1/2*m*V2

    or

    V2 = 2*g*h
     
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