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Homework Help: Free Fall Question please help

  1. Sep 6, 2015 #1
    1. The problem statement, all variables and given/known data
    A rock is thrown straight down with an initial velocity of 10.5 m/s from the Verrazano Narrows Bridge in New York City. The roadway of this bridge is 70 m above water. Take upwards to be the positive direction.

    Calculate the displacement and velocity at a time of 1.0 s.

    The attempt at a solution
  2. jcsd
  3. Sep 7, 2015 #2
    So what is your question?

    Can you give some more details on how you ended up with that answer?
  4. Sep 7, 2015 #3
    I've figured out the displacement by (10.5)(1)+(1/2)(9.8)(1.0)^2=-15.4
    I don't know how to find velocity though.

  5. Sep 7, 2015 #4

    So, you have used the gravitational acceleration 9.8m/s^2 to calculate the displacement.

    What is the definition of acceleration?
  6. Sep 7, 2015 #5
    rate of change of velocity

  7. Sep 7, 2015 #6
    Right. So the acceleration is constant, and you are given with initial velocity. You can now calculate the velocity at t = 1.0 s.
  8. Sep 7, 2015 #7
    Awesome! Thanks a lot

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