Peter, I basically agree with you. I chose the inflection point because it is relatively easy to find and it would seem to be a point of some significance because it is the point on the graph where the slope is steepest. Although the horse has probably long since expired, I'll continue to pulverize it just to see if there is any merit to be found. If you lean a boat to a given angle and try to hold it there, the inflection point is the angle where it will be hardest to get the boat to tip any farther. From this point until you reach the maximum of the curve, any increase in tipping force will still be balanced by a righting force, but you are over the hump. From the inflection point on, it will become progressively easier to force the kayak into a capsize. If the top of the curve is the beginning of the end, maybe the inflection point is the end of the beginning. One of the biggest problems I see with the inflection point theory is that many boats don't have an inflection point. For these boats the steepest part of the curve is at zero degrees of heel. I am not ready to say none of those boats have any secondary stability. At the very least I hope that my pointing to the inflection point put a little spot light on the roll played by the slope of the curve. Nick At 1:44 AM -0800 11/21/00, Peter A. Chopelas wrote: >-snip- > >I also question Nick's proposed definition of using the location of the >inflection point as indicative of the perceived secondary stability. If >Matt is not thoroughly confused by now the inflection point is where the >RATE of CHANGE of a curve reverses. For example a strait line from the >"zero, zero" point has a constant rate of change, for each degree of roll >you get the same increase of correcting moment; for a concave curve the >rate of change is increasing, for each additional angel of roll the >increase in correcting moment gets larger, for a convex cure the rate of >INCREASE of correcting monument gets smaller, BUT IT IS STILL INCREASING, >just not as much. If the curve has an inflection point it is where the >RATE of increase reduces below zero so the RATE of change is getting >smaller, it would be where the concave cure meets the convex curve. -snip- -- Nick Schade Guillemot Kayaks 824 Thompson St, Suite I Glastonbury, CT 06033 (860) 659-8847 Schade_at_guillemot-kayaks.com http://www.guillemot-kayaks.com/ >>>>"It's not just Art, It's a Craft!"<<<< *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Tue Nov 21 2000 - 14:05:19 PST
This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:34 PDT