Rotational dynamics, semicircular arc

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Homework Statement


(see attachment)


Homework Equations





The Attempt at a Solution


Do I need to take torque about C here?

Any help is appreciated, Thanks!
 
Attachments
  • Printed problem Q.23: a uniform rod AB bent into a circular arc, pivoted at point C, with angle beta marked at the centre and end B shown below the arc, with a labelled radius and rod ends A and B.
    semicircular arc.jpg
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Do I need to take torque about C here?
How else would you find the angular acceleration?
 
Simon Bridge said:
How else would you find the angular acceleration?

I asked this because I am sure this would involve integrals and before doing the maths, I want to be sure if I am heading in the right direction. :smile:
 
If you can only think of one way to do a problem, it is worth a try: give it a go.
Everything involves an integral if you don't already know the result.

But it can help to have a think about the problem before starting:
* If ##\beta=0##, what is the initial angular acceleration?
* How does the total mass vary with ##\beta##?
* How does the location of the center of mass vary with ##\beta##?
 
Simon Bridge said:
If you can only think of one way to do a problem, it is worth a try: give it a go.
Everything involves an integral if you don't already know the result.

But it can help to have a think about the problem before starting:
* If ##\beta=0##, what is the initial angular acceleration?
* How does the total mass vary with ##\beta##?
* How does the location of the center of mass vary with ##\beta##?

I have solved the problem, I had trouble because I misinterpreted the problem. It looked to me like a semicircular arc but it isn't. Thanks! :smile:
 
Pranav-Arora said:
I have solved the problem, I had trouble because I misinterpreted the problem. It looked to me like a semicircular arc but it isn't. Thanks! :smile:
Yes, it's a poor drawing. The point where those angles meet doesn't look like it's supposed to be the centre of the arc.