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Pencil in elevator

  1. Sep 24, 2009 #1
    A pencil is dropped from inside an elevator moving 5m/s upward. Calulate the time it takes to drop from 1m to elevator floor and its velocity.

    I approached as a velosy problem. Is this more of a Force problem ? I could calculate the velocity and time it took while the elevator was at a standstill, but got stuck when its in motion. Can someone please guide me in the right direction? THanks!
  2. jcsd
  3. Sep 26, 2009 #2


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    maybe show some working so we can see where you went wrong

    note the pencil will initially be moving up at 5m/s the same speed as the elevator & have a think about equivalence of inertial reference frames
  4. Sep 27, 2009 #3
    The concept you should apply is Galilean relativity; the laws of physics are the same in all inertial frames.
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