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Homework Help: Finding time and final velocity

  1. Sep 27, 2009 #1
    1. The problem statement, all variables and given/known data
    A photographer in a helicopter ascending vertically at a constant rate of 12.5 m/s accidentally drops a camera out the window when the helicopter is 60.0 m above the ground.
    -How long will it take the camera to reach the ground? What will its speed be when it hits?
    a= -9.8 m/s^2 displacement=60 m

    2. Relevant equations
    (final v)^2=(initial v)^2 + 2*a*deltax
    deltax=1/2a(t^2)+(initial v*t)

    3. The attempt at a solution
    initial v=0
    so time will equal 3.5 s, and final velocity will equal 33.67 m/s^2
    however, these are incorrect
  2. jcsd
  3. Sep 27, 2009 #2


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    Science Advisor
    Homework Helper

    The initial v is not 0, but the v of the helicopter and photographer. If you don't believe is, look up some movies of a ball shot from a moving car: when the car is moving at 50 km/h and the ball is shot backwards at 50 km/h, it drops straight down.
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