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Homework Help: Really basic Kinematics problem

  1. Jun 10, 2008 #1
    This is doing my head in. It should be really simple, but I just can't work out the reasons why.

    I have a particle of 50g that drops from rest. It drops 1m in 12s.

    I then have to find the final velocity of the particle after this 12s.

    Using v = u + at I get v=12g

    Using h = (u+v)t/2 I get v=1/6.

    This is clearly quite a large discrepancy, andI can't see why. Can anyone put me out of my misery with this please?
  2. jcsd
  3. Jun 10, 2008 #2


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    There is no discrepency. You are simply just not justified in assuming a value for the acceleration.
  4. Jun 10, 2008 #3
    Oh ok thats fair enough. Just assumed I could use g. Obviously not then.
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