1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Centripetal Force Minimum Period Question

  1. Nov 14, 2012 #1
    1. The problem statement, all variables and given/known data
    A boy ties a 3.00kg rock to a 0.70 m string and begins spinning it around in a horizontal circle at a constant speed. If the string will break if the tension is greater than 80.0 N, what is the minimum period for the rock to spinning in a circle. How do i solve this?


    2. Relevant equations

    m4∏^(2 ) r/T^2

    3. The attempt at a solution
    80.0= (3.00)4∏^(2)(0.70)/T^2
    T= 1.02
     
  2. jcsd
  3. Nov 15, 2012 #2

    Delphi51

    User Avatar
    Homework Helper

    Welcome to PF!
    Looks good. I get a very slightly larger answer; might be worth running it through the calculator again.
     
  4. Nov 15, 2012 #3
    Your equations written as pie squared r instead of pie r squared, i think you did it right but it looks weird
     
  5. Nov 15, 2012 #4
    its the equation in the text book. So can you explain how max tension gets minimum period?
     
  6. Nov 15, 2012 #5

    haruspex

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    2016 Award

    Yes, the equation is correct, though it does look odd at first sight.
    The stone has a certain distance to cover, 2πr, in one period. So minimum period means maximum speed, and that means maximum tension.
     
  7. Nov 24, 2012 #6
    Sorry your right, its so weird seeing pie digitally
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Centripetal Force Minimum Period Question
Loading...