More Circular Motion

  1. God, I'm getting so frustrated.

    A 0.50kg ball that is tied to the end of a 1.5m light cord is revolved in a horizontal plane with the cord making a 30 degree angle with the vertical.

    a) what is the ball's speed.

    Now, I drew my little diagram, solved for the force of tension (got 5.66N). I plug that in for my Centripetal Force in

    Centripetal Force = mv^2/r, solve for v, and got 4.1 . The book gets like, 2.1. I'm getting so frustrated right now...let me know if you can help. Thanks.
     
  2. jcsd
  3. HallsofIvy

    HallsofIvy 40,370
    Staff Emeritus
    Science Advisor

    Did you forget to take the SQUARE ROOT???
     
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