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Homework Help: Kinematics one vector problem

  1. Sep 9, 2011 #1
    1. The problem statement, all variables and given/known data
    A hot-air balloon is ascending at the rate of 10 m/s at a height of 84 m above the ground when a package is dropped.

    Find time it took to hit the ground

    Find Final velocity

    2. Relevant equations



    3. The attempt at a solution

    Initially, I am inclined to use the equation Yf = Vot + (1/2)at^2

    I know that a=-9.8 m/s^2
    Vo = 10m/s
    Yf=84m

    With four variables and 3 are known, I can find time.

    The part I am having trouble with is setting up the equation where time is a function of velocty and position (where as t=something)

    Am I even approaching this problem correctly? Any help will be much appreciated.
    ATranPV

    EDIT: Yes...my algebra sucks...:(
     
    Last edited: Sep 9, 2011
  2. jcsd
  3. Sep 10, 2011 #2
    Hint: To solve for t, use the quadratic eaquation.
     
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