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Homework Help: Speed when swinging from a rope?

  1. Feb 2, 2009 #1
    Tarzan swings on a 23.8 m long vine initially inclined at an angle of 36° from the vertical.

    (a) What is his speed at the bottom of the swing if he starts from rest?
    m/s

    (b) What is his speed at the bottom of the swing if he starts with an initial speed of 2.22 m/s?
    m/s

    help please!
    i have no idea how to do this ah!
     
  2. jcsd
  3. Feb 2, 2009 #2
    A)1/2 mv^2 = mgh
    potential energy at the top = kinetic energy at the bottom of the pendulum.

    B)1/2mv^2 + mgh = 1/2 mv^2
    initial kinetic energy plus potential energy at the top = final kinetic energy at the bottom.
     
  4. Feb 2, 2009 #3
    how do i factor in the angle?
     
  5. Feb 2, 2009 #4
    the angle has nothing to do with the energy, only in finding the height.
     
  6. Feb 2, 2009 #5
    how do i use it to find the height?
     
  7. Feb 2, 2009 #6
    really basic trig.
     
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