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Tension in a string last problem.

  1. Oct 22, 2010 #1
    1. The problem statement, all variables and given/known data

    A 1.0 kg pendulum bob is suspended from a string 1.0 m long. The pendulum swings until the string makes an angle of 22 degrees with the vertical. At this point


    2. Relevant equations

    I can't remember

    3. The attempt at a solution


    a.) What is the tension in the string?

    Answer: Ft = mgcostheta Ft = 9.09N

    b.) What is the component of the force of gravity at right angles to the string?

    Answer: Fg = mgsintheta = 3.67N

    c.) What is the acceleration of the pendulum bob?

    Answer: a = gsintheta = 3.67 m/s^2

    d.) If the pendulum is held with a string fastened to the bob and held horizontally as shown, what would be the tension in the original string (not the horizontal one). (3 marks)

    I don't know the answer to part D

    The graph looks like this:

    http://i53.tinypic.com/23rwa5l.jpg

    Thanks.
     
  2. jcsd
  3. Oct 23, 2010 #2
    the tension would be in a way "shared" by both the strings. So drawing a FBD equate vertical and horizontal components and get your answer.
    And your part 1) is wrong too,
    Tcos(theta)=mg

    And i think your c) part is wrong too, use the equation above, if it helps.
     
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