Need The sum of time to calculate speed

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    Speed Sum Time
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Discussion Overview

The discussion revolves around a physics problem involving the calculation of speed for a discus undergoing uniform circular motion, specifically addressing the need for the sum of time in the calculation process. Participants explore the relationship between force, mass, radius, and speed in this context.

Discussion Character

  • Homework-related
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant questions whether the sum of time is necessary to calculate speed, indicating uncertainty about the problem's requirements.
  • Another participant identifies that the discus is in uniform circular motion and provides the equation relating net force to centripetal force, suggesting that the values needed to solve for speed are available.
  • A participant expresses gratitude for the clarification and reflects on their experience as a beginner in physics, indicating a need for more guidance.
  • Another contributor offers encouragement, sharing their own experience of overcoming challenges in physics through hard work and understanding of physical laws.
  • A participant suggests that the problem may be poorly worded and expresses a different interpretation of the force involved, indicating potential confusion about the concepts being discussed.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and interpretation of the problem, with some agreeing on the need for clarification while others highlight potential ambiguities in the problem statement. No consensus is reached regarding the necessity of time in the calculation.

Contextual Notes

Participants note the potential for confusion due to the wording of the problem and the assumptions that may need to be made regarding the forces acting on the discus.

Tumbleweed
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Don't you need The sum of time to calculate speed.
This is the question in my book

A horizontal force of 280 N is exerted on a 2.0 kg discus as it rotated uniformly in a horizontal circle (at arms length) of radius 1.00 m. Calculate the speed of the discus.

I am not he smartest person around but I just for the life of me can not figure how to get the time. am I suppost to assume it.

Thanks
tumbleweed
 
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As far as I can tell, the discus is undergoing uniform circular motion.

[tex]F_{net} = F_{centripetal} = \frac{Mv^2}{R}[/tex]

You know all the values except v for which you need to solve.
 
speed

Thanks
The same formula is in the book but worded diff
That helped a lot
This is my first physics class of many and I can now see it will be along road.
I am taking the class on line and I can see I needed a real class.
Thanks again
Tumbleweed
 
Yes, physics unlike many other classes will be quite difficult without some guidance to help you "unwire" a lifetime of mostly false intuitions about the workings of the natural world. The only advice I have is to stick with it and you will make it through with a good understanding. I never thought of my self as particularly intelligent either, but through hard work, and really thinking through the implications of the physical laws and methods I've learned, I have succeeded and made it through all my classes with A's. My advice to you for success would be the same.
 
Tumbleweed said:
This is my first physics class of many and I can now see it will be along road.
Don't sweat it, it appears to me to be a poorly worded problem. I also would have guessed the force was a torqure accelerating the disk, not the centripedal force on it.
 

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