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Mass on a rotating turntable problem.

  • Thread starter btbam91
  • Start date
  • #1
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[PLAIN]http://img841.imageshack.us/img841/7913/314pw.jpg [Broken]

I'm having a bit of trouble with this one.

So the FBD of the block.

In the y coordinates, the normal equals its weight

in the x coordinates, we have static friction to the left, and is there a force to the right? There as to be right, since it eventually begins translating radially?

Just looking for a little guidance, thanks!
 
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Answers and Replies

  • #2
Delphi51
Homework Helper
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From the point of view of the outside observer, a centripetal force is required to hold the mass in circular motion. This is provided by the force of friction. So you begin with Fc = Ff, put in the details and calculate the speed for which they are just equal.
 
  • #3
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the speed of the turntable and the block or just equal?

omega*R?
 
  • #4
Delphi51
Homework Helper
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Yes, the speed of the turntable omega*R.
Then you can go for the time to reach that speed.
 

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