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Free Falling Object

  1. Oct 8, 2006 #1
    A ball is thrown vertically upward with a speed of 25.0 m/s. (a) How high does it rise? (b) How long does it take to reach its highest point. (c) How long does it take to hit the ground after it reaches its highest point? (d) What is its speed when it returns to the level from which it started?

    What forumulas/equations should I use to use to solve each of those questions?
  2. jcsd
  3. Oct 8, 2006 #2


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    Do you know any basic kinematic equations? What kind of motion is a vertical throw? What is the acceleration?
  4. Oct 8, 2006 #3
    The force of gravity is the only force that will act upon the object.

    You can use Y=Yo+Voyt+.5(g)(t)^2 to calculate the height and the time.

    Use Vy=Vyo+gt to solve for the time.
  5. Oct 8, 2006 #4
    Btw, I think those are the correct equations lol. I'm new to Physics myself. Just remember that the velocity decreases 10m/s each second because of gravity. So if you throw an object up 40m/s it would take 4 seconds for it to reach it's highest point because the velocity decreases 10m/s each second.

    g= -9.8m/s^2 , rounded= -10m/s^2
  6. Oct 8, 2006 #5
    I see.. What does y represent?

    EDIT: nvm, I found it in the book.
    Last edited: Oct 8, 2006
  7. Oct 8, 2006 #6
    Just think of y as the y axis or the height and x as the x axis(horizontal) or the displacement, distance.
  8. Oct 8, 2006 #7
    Also the time it takes to hit the ground from the highest point. Think of the problem as a parabola.. Well an upside down parabola. =]
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