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Homework Help: Whirling around a mass to find max force of tension

  1. Mar 25, 2013 #1
    1. The problem statement, all variables and given/known data
    An object of mass 3.0kg is whirled around in a vertical circle of radius 1.3m with a constant velocity of 6.0m/s. Calculate the maximum and minimum tension in the string.

    mass=3.0kg
    v=6.0m/s
    radius=1.3m


    2. Relevant equations
    Fc=mv2/r
    Fun=ma


    3. The attempt at a solution
    Here is my fbd where I show the mass when it is at the highest point and the lowest point.
    tumblr_mk8o9cUBvL1qe908uo1_500.jpg

    When it reaches top:
    ƩFy=mac
    Fc-Fg-Ft=0
    Fc-Fg=Ft
    (mv2/r)-mg=Ft
    Ft=53.7N ∴minimum tension

    When it reaches bottom:
    ƩFy=mac
    Ft-Fg-Fc=0
    Ft=Fg+Fc
    Ft=mg+(mv2/r)
    Ft=113N ∴maximum tension
     
  2. jcsd
  3. Mar 25, 2013 #2

    rude man

    User Avatar
    Homework Helper
    Gold Member

    Good! (I didn't check the math. The formulas are right).
     
  4. Mar 25, 2013 #3
    :surprised
    Awesome!!! Good to hear!! :blushing: Once again, thanks for taking your time to look it over for any errors heh
     
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