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Calculating Speed of a motion of a Circular Object

  1. Jan 22, 2009 #1
    1. The problem statement, all variables and given/known data

    A conical pendulum is made of a ball on the end of a string, moving in circular motion as represented in the figure below. The length L of the string is 1.70 m, the angle θ is 37.0o, and the ball completes one revolution every 2.30 s.

    Calculate the speed of the ball, by first deriving a symbolic equation and then inserting the
    numbers.

    2. Relevant equations



    3. The attempt at a solution

    I sort of know how to do this problem without the degrees.
     
  2. jcsd
  3. Jan 22, 2009 #2

    LowlyPion

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    Homework Helper

    I can't see the picture, but I presume that it is rotating in a horizontal plane.

    First of all you know that the ball is describing a circle that has a radius of L*Sin37°.

    You know the time to complete a revolution ...
     
  4. Jan 24, 2009 #3
    Alright, here is what I got

    R=L*sin(37)

    R=1
    Diameter=2
    Circumference=pi(2)

    Circumference=6.3

    Speed=Distance Traveled/Time

    Speed=6.3m/2.3s

    = 2.7m/s

    Is that right?
     
  5. Jan 24, 2009 #4

    LowlyPion

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    Looks about right.

    I get 1.02 m

    and 6.41 and 2.79.
     
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