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Acceleration of a ball thrown upwards.

  1. Oct 11, 2008 #1
    1. The problem statement, all variables and given/known data
    A ball is thrown up the top of the tower. At each of the following instants is the ball's acceleration larger than g, equal to g, or -g (assume up is positive, g=9.8m/s2)
    a) Just after leaving your hand?
    b) When the ball is at its highest point?
    c) Just before hitting the ground?

    2. Relevant equations

    3. The attempt at a solution
    a) -g
    b) -g
    c) g
  2. jcsd
  3. Oct 11, 2008 #2
    Your answers are not all correct: but you should say more about how you arrived at your answers. If they are random guesses then you should try harder.

    In any case, I suppose air friction is neglected here, otherwise the correct answer is not always among the 3 choices!
  4. Oct 11, 2008 #3
    well the first two answers.. since the ball is moving up.. it is eventually going to reach a velocity of 0, so it slows down.. so acceleration is -g... And when it is moving down... the velocity gets faster and faster.. so i would assume that the acceleration would be g
  5. Oct 12, 2008 #4
    Maybe you're confusing speed and velocity: it's not just about "speeding up" or "slowing down," [which refer to speed, really] it's the direction of the change in velocity which is important.
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