# Rolling without slipping down an inclined plane

• dyn
In summary, the conversation discusses the concept of rolling without slipping and the role of friction in this scenario. It is determined that static friction is responsible for maintaining rolling without slipping and that kinetic friction can cause the initial slipping before rolling begins. The conservation of mechanical energy can be used in cases where static friction does work, as long as it is the only force doing work.
The Nomenclature is not recognized by the disc or the inclined plane. Get it?

Ehyeh Asher Ehyeh said:
The Nomenclature is not recognized by the disc or the inclined plane. Get it?
But the formulas are “recognized by the disk” in the sense that one of them correctly describes the behavior of the disk and the other does not. The nomenclature serves to identify which formulas to use.

The disc and plane are indifferent to your use of language. The behaviours do not depend on Semantics. That is unless you are talking Voodoo?

weirdoguy
dyn said:
When a ball/disc slides down an incline plane , the point of contact is moving relative to the surface so the external torque that causes the ball/disc to start rotating is kinetic friction.
IF the ball starts out sliding this is correct. However, note that it is possible (in fact common) for the ball to start rotating in the static friction condition from the beginning. In such cases there would be no “instant the rolling without slipping condition is met” because it would always be met.

An example would be a ball at the top of a rough ramp held in place at the top for a time and then released to roll under gravity. Such a ball would be in the no-slip condition from the beginning.

dyn
Ehyeh Asher Ehyeh said:
The disc and plane are indifferent to your use of language. The behaviours do not depend on Semantics. That is unless you are talking Voodoo?
I am not talking about semantics at all. Why are you?

Physics is great ! You ask a seemingly simple question and it always ends up getting so much more complex. Thanks everyone for replying to this thread

Ehyeh Asher Ehyeh and Dale
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