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Homework Help: Another energy conservation problem

  1. Oct 17, 2006 #1
  2. jcsd
  3. Oct 17, 2006 #2
    I believe I'm right in my method here, although I didn't do to well in kinematics:

    PE=mgh
    KE= 1/2mv^2

    At the start you only have PE since velocity=0. When you fly off you have both PE and KE

    So due the conservation of energy we have:

    PE(i)+KE(i)=PE(f)+KE(f)

    Furthermore:

    PE(i)=PE(f)+KE(f)

    h = r

    mgr=mgr+1/2mv^2

    Do the algebra to get the final velocity (Things cancel, you get a number). That should get you started. If I'm wrong, well maybe you can get an idea from what I posted here.
     
  4. Oct 18, 2006 #3
    I don't know. I am suppose to solve for the angle, but there are no angles in the equations you gave me.

    mgr-mgr = (1/2)mv^2
    0 = (1/2)mv^2

    which is not true
     
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