Comments for The Basic Physics and Mathematics of Table Tennis at http://www.gregsttpages.com/gttp , comment 1 to 6 out of 6 comments http://www.gregsttpages.com/gttp Wed, 10 Mar 2010 08:58:16 +0100 FeedCreator 1.7.3 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-100 I'll repeat once again - I'm not a physics guru, so if you are and you think this article is incorrect, by all means send me your version and I'll be happy to put it up on the site as well for contrast. But so far nobody has bothered to supply me with a "correct" version, and god knows I'm not going to try to write one, and in any case the article stays because Jon took the time to write it. - GregLetts_OC Tue, 22 Sep 2009 02:07:33 +0100 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-97 This article should be removed because people who read it might believe it and be fooled by it. The crushed feelings of the author is nothing compared to the harm done by spreading fake knowledge to people. - LBuhnemann Tue, 15 Sep 2009 21:25:27 +0100 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-60 What is the need to remove the page from the site? If you don't like the content just dont read it. :) Jonathan has clearly gone to alot of trouble in writing this article - I doubt you guys have even realised the guys feelings your crushing. All I want to say is please have ppl's fealings in mind in future even though you may be 100 percent in the right - Jeremy Wed, 22 Apr 2009 17:06:13 +0100 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-47 > time the ball is in contact with the racquet which is fixed at approximately 0.003 seconds The time will vary a bit, depending on the amount of deformation of the rubber. The duration would be shorter with a firmer and/or harder rubber surface than it would with a larger and/or softer rubber surface. The harder the ball is struck, the more deformation (of both ball and rubber), and the longer the duration. > P = W÷t Change in kinetic energy is related to work done, not directly to power (which is a rate of work done). >W = Fs >If the amount of Force is increased, then the Work coefficient is increased. The other way is to increase the >displacement, but that cannot be done as the length of the Table is fixed The work done is related to the force times the distance the ball moves while in contact with the racquet. The length of the table has nothign to do with the work done by striking the ball with a racquet. Increaseing blade speed will increase both force and the distance the ball is in contact with the racquet, resulting in a greater change in kinetic energy. >spin - relative air speed Relative air speed doesn't matter (otherwise static ports on aircraft wouldn't work), it's the change in air speed and/or direction that matters. This web site covers Magnus Effect reasonably well: http://www.geocities.com/k_achutarao/MAGNUS/magnus.html - Anon Sat, 28 Mar 2009 14:31:09 +0100 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-43 Thanks David - as I've said before, anybody who wants to write their own version which they feel is better is welcome to send it to me and I'll put it up on the site as well for comparison and contrast. Four years later and I'm still waiting for anybody with a physics background to do so. Jonathan took the time to write an article, so that's why his version is up on the site. I'm no physicist, so don't expect one from me! ;) - Greg Letts Tue, 17 Mar 2009 23:27:56 +0100 http://www.gregsttpages.com/gttp/index.php/General-Articles/the-basic-physics-and-mathematics-of-table-tennis.html#comment-42 Honestly Greg, This page should be removed as it's mostly complete junk. Example: the explanation of how spin affects the ball's flight is wrong and the correct explanation (an increase in pressure on one side of the ball) can be found in many freshman level physics textbooks. - David Bernstein Tue, 17 Mar 2009 21:24:02 +0100