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Rotational Dynamics

  1. Mar 25, 2007 #1
    1. The problem statement, all variables and given/known data
    A 10kg objects rotates on a point on a wire 3 meters long at the rate of 120 rad/sec without breaking the wire.

    1) What is the numeric value (and units) of the velocity vector and 2)what angle does it make with the tangent at any point? and 3) What's the minimum tensile strength of wire asumming that is has a 50% safety factor? (Minimum tensile strength of the wire is 1.5 times the working tensile strength)

    Please answer or help me with atleast 1 and 2

    2. Relevant equations
    problemset16.jpg or V=ωr or θ=S/r

    3. The attempt at a solution
    V=120(3)= 360 m/sec

    α= 43200

    t= (Vf-Vi)/a
    t=.00833 seconds

    theta=120(.00833)= 1

    please help.
    Last edited: Mar 25, 2007
  2. jcsd
  3. Mar 26, 2007 #2

    Doc Al

    User Avatar

    Staff: Mentor

    That's the correct approach and answer for question 1.

    That's the centripetal acceleration. Now apply Newton's 2nd law to work out the tension.

    No clue what you are doing here.
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