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Homework Help: Impulse Question (Really Difficult)

  1. Nov 15, 2007 #1
    1. The problem statement, all variables and given/known data
    A bird is initially perched on a swing with a mass of 153 g. The bird has a mass of 52 g. The swing is 8 cm below the point of attachment to the top of the cage. The bird/swing are initially at rest. The bird takes off horizontally at 2 m/s. How high will the base of the swing rise above its original level? Disregard friction.

    2. Relevant equations
    Where do i start?

    3. The attempt at a solution
    ive used several formulas that dont work out i just need to know which formula to use im completely and utterly lost on this problem. Ive tried m1v1 + m2v2 = m1v1f + m1v1f , didnt work. and mgh = 1/2mv^2. Any help ? :(
    Last edited: Nov 15, 2007
  2. jcsd
  3. Nov 15, 2007 #2


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    What's the momentum of the bird when it leaves? The perch will have an equal and opposite momentum backwards. (This is treating the bird as more of a projectile than a flyer - but I think that's the intent of the problem).
  4. Nov 16, 2007 #3
    sweet thx dood! :) (I figured it out)
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