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Homework Help: Need some help to answer Some questions

  1. Feb 14, 2006 #1
    Hi Guys,

    I face some problems answering below questions. Anyone can help to answer?

    Q1: One end of a string of length 1.0m is tied to body of mass 0.5kg. It is whirled in a vertical circle. If its angular speed is 3rev/s, calculate the tension in the string at the highest and lowest points.

    Q2: (a) Calculate the angular speed of the earth.
    (b) Calculate the
    (i) Energy
    (ii) Torque and (iii) average power
    required to accelerate the Earth in 1 day from rest to its present angular speed.
    (Mass of the Earth : 6x10 power 24 kg , radius of erath = 6400km)


  2. jcsd
  3. Feb 14, 2006 #2
    We cannot just give you the answers, that's against the PF Guidelines. Please show us what you have done so far.


    ps : as a hint to Q1. Can you link the orbital velocity to an acceleration (centripetal) ? There is a nice and easy formula for this. If you do this, you are on your way...
    Last edited: Feb 14, 2006
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