Friction as centripetal force....problem with the mass

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Homework Help Overview

The discussion revolves around a problem involving two masses (5 kg and 1 kg) undergoing circular motion at the same radius with a constant coefficient of friction. Participants are exploring how varying angular speeds affect the point at which each mass ceases circular motion, particularly focusing on the role of centripetal force and friction.

Discussion Character

  • Conceptual clarification, Assumption checking, Mixed

Approaches and Questions Raised

  • Participants are questioning whether the larger mass will stop circular motion first due to requiring more centripetal force, while others argue that both masses should stop simultaneously based on the equations provided. There is also discussion about the implications of friction and the conditions under which the experiment is conducted.

Discussion Status

The discussion is ongoing, with participants presenting differing viewpoints on the relationship between mass, friction, and centripetal force. Some have suggested that experimental conditions may influence the outcome, while others are seeking clarification on the setup and assumptions involved.

Contextual Notes

There are mentions of insufficient details regarding the experimental setup, such as the nature of the surface on which the masses are placed and the distances of their centers of mass from the rotation axis. This lack of information is affecting the clarity of the discussion.

Geo louv
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Homework Statement



The problem is that if I have a 5kg mass and 1 kg mass at the same radius with the same μ...and I increase slowly the angular speed ω...then the first mass that will stop the circular motion is the one of the 5 kg mass because needs more centripetal force.Can someone say that this is not true and the two objects will stop at the same time the circular motion because ofthe equations T=m(u^2)/r μΝ=m(u^2)/r μ(mg)=m(u^2)/r. μg=(u^2)/r. ?
2. Homework Equations

The Attempt at a Solution

 
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I have big problem...because if you see the equation μg=u^2/r you can assume that the two objects will leave at the same time...
 
Geo louv said:
.Can someone say that this is not true and the two objects will stop at the same time
This is not true.
 
Yes if you see the equation F=mω^2R...then you will come to the conclusion that the one with the bigger mass will stop first to moving circular because need more centripetal force.....Yes but also at the bigger mass I have bigger friction...T=μΝ. Τ=μ(mg)...so why two masses are not stopping the circular motion at the same time??
 
They should stop at the same time.
 
No...if you do the experiment the bigger mass stop first the circular motion
 
Geo louv said:

Homework Statement



The problem is that if I have a 5kg mass and 1 kg mass at the same radius with the same μ...and I increase slowly the angular speed ω...then the first mass that will stop the circular motion is the one of the 5 kg mass because needs more centripetal force.Can someone say that this is not true and the two objects will stop at the same time the circular motion because ofthe equations T=m(u^2)/r μΝ=m(u^2)/r μ(mg)=m(u^2)/r. μg=(u^2)/r. ?
2. Homework Equations

The Attempt at a Solution

This problem is not well defined. You haven't given enough details.

From the sparse description, I don't see how centripetal force is involved at all.
 
image.jpg
 
But m1 has also bigger friction...because of the bigger mass...so they must leave at the same time
 
  • #10
Geo louv said:
No...if you do the experiment the bigger mass stop first the circular motion
Please describe the experiment in detail. Are they both resting on a flat rotating surface, perhaps? What are the shapes and widths of the objects, and how far are their mass centres from the axis?
 
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  • #11
Haruspex you are GENIUS...OF course if it is a float rotating surface...they will stop rotation at the same time...,but if it's not...and the maximum Ts is the same then...the bigger mass will stop rotation first
 
  • #12
Geo louv said:
Haruspex you are GENIUS...OF course if it is a float rotating surface...they will stop rotation at the same time...,but if it's not...and the maximum Ts is the same then...the bigger mass will stop rotation first
Please describe the experiment in detail.
 

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