Do heavy and light cylinders roll the same?

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    Cylinders Light Roll
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Discussion Overview

The discussion centers on the behavior of heavy and light cylinders rolling down an inclined plane without slipping. Participants explore the effects of mass, radius, and moment of inertia on the rolling motion, considering both straight and potentially curved slopes.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant notes that in a vacuum, heavy and light items fall the same distance in the same time, and questions whether this holds for rolling cylinders on an incline.
  • Another participant references a previous derivation related to the topic, suggesting that there may be established calculations available.
  • A later reply introduces uncertainty about the generalization of results to curved slopes, indicating that the path traced by the center of mass may vary based on the cylinder's radius.

Areas of Agreement / Disagreement

Participants express uncertainty regarding the generalization of results to different types of slopes, indicating that multiple competing views remain on how mass and shape affect rolling motion.

Contextual Notes

There are limitations regarding the assumptions made about the slopes being flat versus curved, and the implications of varying moments of inertia based on density distribution within the cylinders.

Gary_1
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I understand why a heavy item and a light item both fall a given distance in the same time - in a vacuum, etc.

What happens in the case of a cylinder rolling down an inclined plane with no slippage? Would a heavy cylinder reach the bottom at the same time as would a light cylinder? What if the cylinders were of differing radii? What if the cylinders had a differing moment of inertia, e.g., one cylinder with homogeneous density versus another that was of higher density nearer the surface of the cylinder?

Thansk for helping me understand.
 
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Thinking about it more, I'm actually not entirely sure if that statement generalizes to arbitrarily *curved* slopes. For cylindrical objects my calculation is correct. The catch is that the height refers to the center of mass and the center of mass might trace out shorter or longer paths (depending on the radius of the cylinder) if the slope isn't flat but curved. Hmm...
 

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