1. Limited time only! Sign up for a free 30min personal 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!

Calculating Tension of a bob moving in horizontal circles

  1. Mar 20, 2012 #1
    Could someone please look at the problem below and see if i am on the right lines of solving it? I am finding the whole subject of circular motion hard to get my head around and therefore not 100% confident in my workings. I have also attached my free body diagram.

    1. The problem statement, all variables and given/known data

    Calculate the tension in a 3m string attached to a 3kg bob that is moving in horizontal circles of 0.6m radius

    2. Relevant equations

    Tanθ = Opposite/Hypotenuse

    TCosθ = mg

    3. The attempt at a solution

    θ = Tan-1 0.6/3
    θ = 10.32°

    TCosθ = mg
    T = mg/Cosθ
    T = (3Kg x 9.81) / Cos 10.32
    T = 29.91 N
     

    Attached Files:

  2. jcsd
  3. Mar 20, 2012 #2

    Doc Al

    User Avatar

    Staff: Mentor

    The radius over the hypotenuse would equal sinθ, not tanθ.

    Other than that, you're doing fine.
     
  4. Mar 20, 2012 #3
    Thanks for that i have just noticed i used TAN not SIN for my workings myself which obviously changes my final answer slightly. Thanks for the reassurance i'm on the right track. I have spent many long hours trying to get my head around this whole subject.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook