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Homework Help: Rock on a string

  1. Mar 19, 2012 #1
    1. The problem statement, all variables and given/known data
    so theres a 6 kg rock spinning in a circle with a string that can with stand a maximum tension of 75 and a radius of 1.5m
    and i need to find the maximum speed before the string will break

    2. Relevant equations


    3. The attempt at a solution
    so Fnet =ma and a = 4[itex]\pi[/itex]2R/T2
    so Fg = m*4[itex]\pi[/itex]2R/T2
    so 6*9.8 = 6*4[itex]\pi[/itex]21.5/T2
    so 58.8 = 284.24 / T2
    so T = 2.2

    no would i be able to use this formula a=4[itex]\pi[/itex]2R/T2 to find the acceleration and then use a= v2/R to get the speed?
    Last edited: Mar 19, 2012
  2. jcsd
  3. Mar 19, 2012 #2
  4. Mar 20, 2012 #3
    no nothing?
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