| Back In The Saddle |
Mon Nov 23, 2009 06:52pm |
Quote:
Originally Posted by Kajun Ref N Texas
(Post 637825)
No.
I'll go back to the original, SIMPLE point - if the rim and net are included in the BI rule, the backboard should be included also. Touching the backboard is more likely to alter the ball than touching the net.
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That's interesting. Almost all player contact with the backboard I have ever noticed has been from the front, more or less directly into the backboard. And, not surprisingly, that is the one direction in which most backboards are most strongly braced to prevent movement.
Reaching way back to my HS physics class (and the more scientifically inclined will correct me if I'm wrong here), I recall there are some other complicating issues involved too. There's the matter of the mass of the backboard, especially a glass backboard. That much matter is going to strongly resist any impetus applied to it. A material suitably stiff to make a good backboard will lack the elasticity required to be a good carrier of transverse wave energy. A backboard's size relative to the size of the rim mount site means that any wave that is set up will dissipate somewhat before reaching the rim mount site. (Iirc, wave energy dissipates at a rate equal to the square of the distance from the center of the wave) Padding along the edge of the backboard will have a dampening effect on wave energy that might otherwise be reflected from the edge of the backboard material back into the backboard. Need I point out that the most padded surface of all is the bottom, just below the rim? For a glass backboard in particular, I would expect the manufacturer to place a buffer material between the rim and the glass, and probably line the holes between the shafts of the bolts and the glass. This material would exist to resist energy applied to the rim being transferred to the glass. Otherwise you risk cracking the glass every time a ball hits the rim. That energy transfer resistance would likely operate in both directions. On glass backboards the rim must also be attached to the backboard frame so that it cannot come crashing down if the glass breaks. Wave energy transferred via this additional attachment point is almost certain to be out of phase to some degree with waves transferred from the glass itself, further reducing the total wave energy transferred to the ring.
There are obviously a lot of variables based on how a backboard is constructed and braced and how the rim is attached. And I am not saying that it's impossible to shake the rim by hitting the backboard, obviously it is possible. But the physics involved means a player must apply a significantly greater force to the backboard to achieve the same movement caused by simply hitting the rim.
Are you certain you want to treat touching the backboard the same as touching the rim? |
