Yeah, I used a very idealized model for my explanation. Of course you´re right, there are still many more influences that affect the movement. So based on your post, I´ll put it like this:
(Mar. 04, 2016 3:07 PM)Cake Wrote: with the same launch force, RPMs are higher when the Beyblade has lower moment of inertia, which usually means lower weight and/or more inward weight distribution.
Exactly. This is what I said in my first post: The more the weight is gathered in the center, the faster it spins.
(Mar. 04, 2016 3:07 PM)Cake Wrote: Grip is based off of the normal force and the frictional coefficient of the tip on the stadium floor.
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Also, consider the possibility of a heavy Beyblade deforming the rubber tip somewhat; to make the energy transfer as efficient as possible, the tip should only be contacting at a single point - as little surface area as possible. Any more than a single point acting with a tangential force and you start getting more and more friction losses as the tip is twisted against the Stadium floor.
Again right and actually what I said earlier, just in other words. Grip depends on the normal force (which is caused by the weight) and the frictional coefficient. So the normal force depends on the mass, but not the mass distribution. What gets down to the tip is the same, if the mass of the WD is the same. Same goes for deforming the tip. So in the following deliberation, I assume that we have two beyblades, exactly the same base, SG, AR, bit chip, and WD´s that differ only in mass distribution, but have exactly the same weight.
I agree that RPM affect the grip as well - basically the faster it spins the less friction there is in the end, because static friction is overcome more and more. The less frictional connection, the less force transmission and with that less movement through the stadium.
Gather mass in perifer --> higher moment of inertia --> less RPM --> more friction --> more force transmission --> more movement.
That is basically what the beywiki article says. But the problem is, that this goes only for tips with a really flat rubber tip with a high frictional coefficient, because this is the only precondition that can make good use of the weight being gathered at the perimeter: You do need a frictional connection between the beyblade and the stadium. If you have a very low frictional coefficient (let´s say close to zero), there still wouldn´t be much friction, force transmission and with that, speed. The beyblade would only spin slower and have more hitting force, but the same speed around the stadium. An example could be a base with metal tip. Unlike a rubber tip, weight distribution to the perimeter would indeed make it slower, but since there´s not even close as much friction than when using the rubber tip, the effect of weight distribution would be negligible.
So what we can say until now is that the higher the frictional coefficient of the tip is, the more the effect of the increased frictional connection compensates the slower rotation and with that, increases movement.
But yet, there´s still an unfelicitous phrasing in the same sentence. I´ll quote it again: "It is lightweight and the little weight it has is focused around the perimeter of the Beyblade. Both of these features attribute to a high movement speed."
As we agreed before: More weight --> more normal force --> more friction --> more force transmission --> more speed.
Or the other way round: Less weight --> less normal force --> less force transmission --> less speed.
I am NOT going to say that light weight is bad for attack types!! It is obvious that light weight is decreasing the moment of inertia of a moving body not only for its rotation, but also for translation. The more light-weighted something is, the easier it can be set into motion, that´s unworthy of discussion. Sure, higher weight means higher normal force, more friction, more force transmission and so also a certain degree of speed improvement (like discussed before). But a lower moment of inertia increasing the acceleration of the whole beyblade through the stadium even more is obvious.
My point is only about the phrasing: Light weight itself decreases friction and improves the ability of
being accelerated, whereas gathering weight at the perimeter increases friction (in combination with a highly frictional tip) and with that leads to
active acceleration. So this shouldn´t be put in the same sentence, because it´s lightly mistakeable.
My suggestion for the article would be:
"It is lightweight, which allows a high speed movement through the stadium by reducing its inertia. Furthermore, the weight being focused on the perimeter of the Beyblade in combination with high frictional properties of the tip, such as rubber grip, adds speed as well.”
Please th!nk about it...