Actually both angles are the same.
It is the distance that you travel on a sphere that changes the angle slowly.
Why?
You are not traveling in a straight line, but a curved line.
Jim...
Super Secret Settled Science of Sailing?
- Thread starter Will Gilmore
- Start date
It is the distance that you travel on a sphere that changes the angle slowly.
Why?
You are not traveling in a straight line, but a curved line.
Jim...
The "LIFTing Force" on curved sail is a minor force when compared to the force of the wind on say a Flat plate.
Square riggers had the ability to change the angle of the "Flat Plate"
So improve the "Lift" force on a Sail, do as aviators do, add mechanical "Flaps" to the trailing edges of your sail.
Jim...
PS: The Bernoulli EQUATION is not a Law and does not appear in a "Physics" book.
Square riggers had the ability to change the angle of the "Flat Plate"
So improve the "Lift" force on a Sail, do as aviators do, add mechanical "Flaps" to the trailing edges of your sail.
Jim...
PS: The Bernoulli EQUATION is not a Law and does not appear in a "Physics" book.
No, it is a relationship not a law, however...
In "Physics for Students of Science and Engineering," by Halliday and Resnick, probably the pre-eminant university text for 6 decades, it is covered in some depth. Millions of scientists and engineers have been educated using this text.
Feel free to flip through the linked PDF. Chapter 14, pages 374-377.
http://people.unica.it/vincenzofior...y-Fundamentals-of-Physics-Extended-9th-HQ.pdf
This is true, but. The protractor measured angle will be different because it sets you on a different heading than the one measured by the compass. When traveling along the surface of a sphere, all straight lines are great circles. However, steering by compass heading along a latitude line actually steers you in a curve. By traveling only great circles segments, you end up with triangles, and by extension, squares, that have more degrees in them than they do in flat plane geometry.Actually both angles are the same.
Triangles on a sphere have greater than 180 degrees and less than 360 degrees. As long as you define your triangles to always have inside angles less than their outside angles.
-Will (Dragonfly)
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,991
Which MAP projection am I using?
https://en.wikipedia.org/wiki/Map_projection#Which_projection_is_best?
https://en.wikipedia.org/wiki/Map_projection#Which_projection_is_best?
Last edited:
Surely you know, that's a can of different worms. All together.
"that's a can of different worms."
Ok ok, I'll stop calling you 'Surely'
-Will (Dragonfly)
Yes. These non-Eclidean geometric models are simply 2 dimensional models of 3-D space because their use is only concerned with the surface as though it was in only 2 dimensions. We navigate across the surface of the Earth as if we only have 2 dimensions to work with.
-Will (Dragonfly)
The results of turning an actual 90 degree angle at each corner of a journey across the globe and following a straight-line course between turns would be to sail in a closing spiral. The smaller the area covered, the closer to a true square you would trace.
-Will (Dragonfly)
-Will (Dragonfly)
jssailem
SBO Weather and Forecasting Forum Jim & John
- Oct 22, 2014
- 21,991
No argument here. But the question you asked involved a tool used for a 2 dimensional task. I therefor needed more data i.e. which type of two dimensional representation of the globe (a sphere) may I use. Then I may more closely identify the answer to the primary question as modified by the altered assumption.
Here's a Wikipedia page that lists the multitude of projection types. I think standard USCG nav charges are Mercator projections.
-Will (Dragonfly)
-Will (Dragonfly)
Actually the Bernoulli expression is a simplified local model of the 3 dimensional model of the...
Continuity Equation
Feel free to simplify it to the Fluid Dynamics part for 2 dimensions.
Jim...
Your statement was that Bernoulli "does not appear in a 'Physics' book," and that is all I responded to.
Actually the Bernoulli expression is a simplified local model of the 3 dimensional model of the...
Continuity Equation
Feel free to simplify it to the Fluid Dynamics part for 2 dimensions.
Jim...
I did plenty of "something-transfer" classes back in school, in lots of dimentions. The thread has declined into a pissing contest.
This is SailsCallLounge and Physics, which before Einstein, did what you suggested.
If you go to a Modern Physics class you will not find Fluid Dynamic as part of the course.
Here, I can push back on anyone [excluding politics and religion].
The word Physics, in todays world, has morphed into meaning "Anything not understandable and to lazy to web search it"
_______
If I head due West from California, what large land mass would I hit?
Jim...
Wouldn't that be a case of applied fluid dynamics?
I'm sorry you feel that way. It wasn't how I was seeing it.
In going back and reading some of the recent posts, it seems I missed some of them. So my responses appear a little disconnected.
-Will (Dragonfly)
Stream flow for sure.
1) If you are standing on the fore deck and Pizz on the unfurled head sail, does the boat move faster?
2) Pizz overboard instead, does the boat move faster?
3) Pizz on the helmsman, does the boat move faster?
Jim...