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Homework Help: Solving for t

  1. Sep 2, 2007 #1
    1. The problem statement, all variables and given/known data

    0=−(4.90 m/s^2)t^2 -(8.00 m/s)t + 30m
    i am asked to solve for x but having problems
    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Sep 2, 2007 #2

    bel

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    There's no "x" in the equation, but if you are solving for "t", use the quadratic equation.
     
  4. Sep 2, 2007 #3
  5. Sep 2, 2007 #4
    k thanx but im still kind of stuck is -8.00t b and -4.90 a and 30 c. for the quadratic formula
     
  6. Sep 2, 2007 #5

    bel

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    The determinant of the second degree equation is positive, which thereby yields two distinct real roots.
     
  7. Sep 2, 2007 #6
    im sorry but can u explain that simplier
     
  8. Sep 2, 2007 #7

    bel

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    Well, the thing inside the radical sign, it is positive, sqrt((-8.00)^2-4*(-4.90)(30))=sqrt(652), which is real.
     
  9. Sep 2, 2007 #8
    thanks a bunch
     
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