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Homework Help: Quick conversion ?

  1. Mar 14, 2005 #1
    how would i convert 23 degrees to revolutions per minute
  2. jcsd
  3. Mar 14, 2005 #2
    It depends on how long it took you to traverse that 23 degrees, I believe...
  4. Mar 14, 2005 #3


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    Rev's per minute is HERTZ times 60 in SI...Arch degrees is unitless.

  5. Mar 14, 2005 #4
    A conical pendulum is formed by attaching a 0.100kg ball to a 1.00m-long string, then allowing the mass to move in a horizontal circle of radius 40.0cm.
    What is the ball's angular velocity, in rpm?
    from using sin, i obtained 23.57 degress. im not sure how i would convert that to rpm
  6. Mar 14, 2005 #5


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    You appear in this thread and others to be just blindly applying random functions like sin to all the numbers given in your problems, perhaps hoping to accidentally stumble across the right answer.

    This is not a good method of solving problems.

    Instead of telling us that you used the sine function, why don't you tell us what led you to want to use the sine in the first place? What is your thought process? How are you attempting to solve this problem?

    - Warren
  7. Mar 14, 2005 #6


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    You have an angle.However,the angular velocity is found by drawing forces and writing the second law.

  8. Mar 14, 2005 #7
    ok. the first part of the problem asked me to find the tension in the string. to do that i used newtons second law where Tcos(theta)=mg
    to find theta, i looksed at the picture, and since the radius(opposite side of the angle) and the hypotenuse were given, i applied sin, which was sin(theta)=r/l, which ledt to arcsin(.4/1) and i got theta to equal approximately 23 degrees. now for the second part of the problem, so far i could only think of finding the vlocity by the equation v=(omega)*(r), but then im not sure how i would be able to convert velocity into rpm.
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