how a sail works, who can help me explain?
 

how a sail works, who can help me explain?
 

On Wed, 23 Jul 2003 11:34:39 +1200, The_navigator© wrote:

But it's not accelerating -or is it?

Technically, that depends on your reference frame. Let's consider the earth
stationary and the rock stationary. Therefore it is not accelerating. Does F=ma
still apply?


S/V Cat's Meow
http://www.catsmeow.org

how a sail works, who can help me explain?
 

If the rock was truly stationary, there was no Force. Unless we want to get into
immovable objects and unstoppable forces.


"Gerard Weatherby" wrote in message
...
On Wed, 23 Jul 2003 11:34:39 +1200, The_navigator© wrote:

But it's not accelerating -or is it?

Technically, that depends on your reference frame. Let's consider the earth
stationary and the rock stationary. Therefore it is not accelerating. Does F=ma
still apply?


S/V Cat's Meow
http://www.catsmeow.org

how a sail works, who can help me explain?
 

Nav,

I do believe, g linear velocity in a circle is called RPM's

Thanks for taking a good post and destroying it with static

OT

how a sail works, who can help me explain?
 

"Simple Simon" wrote in message ...
Centrifugal force does not exist in any system unless there
is a physical attachment. Twirl a weight on a line and you
will feel what is called centrifugal force. Without the line,
centrifugal force does not exist. There is no line when
air molecules progress around the curved shape of a
sail. There is no centrifugal force either.

If the road turn left and your car can´t follow the curve, what do you
call the force acting on the car and what caused the accident?

You need to base your arguments more on common sense
than isolated quotes and links from professorial types who
never poke their heads out from behind books others have
written who also have no first-hand knowledge.

There are so many physical correct websites on the net so you could
learn more if you were interested:

A Physical Description of Flight ©

http://www.aa.washington.edu/faculty/eberhardt/lift.htm

Bernoulli Versus Newton
http://www.grc.nasa.gov/WWW/K-12/airplane/bernnew.html

What is Ground Effect?
http://home.mira.net/~radacorp/ground_effect.html

Operational use of angle of attack (AOA) on modern commercial jet
airplanes
http://www.boeing.com/commercial/aer...12/attack.html

Weltner Lift
http://www.rz.uni-frankfurt.de/~weltner/
http://www.rz.uni-frankfurt.de/~welt...ht/PHYSIC4.htm

Weltner Bernoulli
http://www.informatik.uni-frankfurt..../MIS/mis6.html

Incorrect theory number three
http://www.grc.nasa.gov/Other_Groups...ne/wrong3.html

Lift from flow turning
http://www.lerc.nasa.gov/www/K-12/airplane/right2.html

Jef Raskin - Coanda Effect: Understanding Why Wings Work
http://www.jefraskin.com/forjef/jefw...da_effect.html

F18 Soundbarrier and highspeed pass
http://www.algonet.se/~newborg/

Beaty Gif pictures smokepuls plus SAAB 2000
http://www.amasci.com/wing/airgif2.html

Prof. Colombinis photogallery
http://www.diam.unige.it/~irro/gallery.html

Flow around an airfoil
http://www.diam.unige.it/~irro/profilo_e.html

ScienceWeb - Aerodynamics
http://www.scienceweb.org/movies/aero.htm


Lift from spinning balls
This website gives a lot of references all back to Newton/Robbins!

The Magnus Effect
http://www.geocities.com/k_achutarao...ew_magnus.html

The Science of Swing, maintained by James Foster
http://www.soest.hawaii.edu/GG/STUDE...ter/swing.html

Normal Swing
http://www.soest.hawaii.edu/GG/STUDE...er/normal.html

Reversed Magnus effect explained
http://www.soest.hawaii.edu/GG/STUDE...r/reverse.html


Wrong lift explanations
Smithsonian
http://www.nasm.edu/galleries/gal109/NEWHTF/HTF510.HTM


False Bernoulli explanations

How things fly, an interactive gallery. Bernoulli Brain-Teasers.
Activities you can do at home
http://www.nasm.edu/galleries/gal109...XT/TEASERS.HTM
US AirForce Museum
http://www.wpafb.af.mil/museum/zone/ff3.htm
Dr. John S. Denker online aerodynamic book. Wrong Lift explanation
explained by "Circulation flow 'creating' the Velocity Field"
http://www.monmouth.com/~jsd/fly/how/htm/
http://www.monmouth.com/~jsd/fly/how/htm/airfoils.html



Jan-Olov Newborg

how a sail works, who can help me explain?
 

"Jan-Olov Newborg" wrote in message om...
"Simple Simon" wrote in message ...
Centrifugal force does not exist in any system unless there
is a physical attachment. Twirl a weight on a line and you
will feel what is called centrifugal force. Without the line,
centrifugal force does not exist. There is no line when
air molecules progress around the curved shape of a
sail. There is no centrifugal force either.

If the road turn left and your car can´t follow the curve, what do you
call the force acting on the car and what caused the accident?

There is centrifugal force felt as long as the car's tires attach it
to the road so the force is felt. As soon as the car leaves the
road and there is no traction from the tires the car goes
in a straight line direction at a tangent from the center of the
curve.

At the moment the traction breaks from the road/tires there
no longer is any centrifugal force. In the case of sails,
there is nothing attaching the wind to the sails so there is no
centrifugal force.


There are so many physical correct websites on the net so you could
learn more if you were interested:

My IQ is close to 150. What can I learn from geeks who
cut and paste information from other sources and do no
independent study of their own. I'm not talking about you,
rather I'm talking about the professorial types who simply
compile research and do none of their own. These are
not authorities in my eyes.

how a sail works, who can help me explain?
 

You tell me!

Cheers MC

Gerard Weatherby wrote:
On Wed, 23 Jul 2003 11:34:39 +1200, The_navigator© wrote:


But it's not accelerating -or is it?


Technically, that depends on your reference frame. Let's consider the earth
stationary and the rock stationary. Therefore it is not accelerating. Does F=ma
still apply?


S/V Cat's Meow
http://www.catsmeow.org

how a sail works, who can help me explain?
 

"The_navigator©" wrote in message
...
You tell me!

Cheers MC

Gerard Weatherby wrote:
On Wed, 23 Jul 2003 11:34:39 +1200, The_navigator© wrote:


But it's not accelerating -or is it?


Technically, that depends on your reference frame. Let's consider the earth
stationary and the rock stationary. Therefore it is not accelerating. Does F=ma
still apply?


S/V Cat's Meow
http://www.catsmeow.org

how a sail works, who can help me explain?
 

Pulls? Wot with invisible strings? Bwhahhahahahahha. You really should
give this up as you don't even begin to understand the Coanda effect!

Cheers MC

Jan-Olov Newborg wrote:
The local lower
pressure pulls in air behind at higher pressure and the airflow
velocity increases.

how a sail works, who can help me explain?
 

Oh No! Another blank post - I'm really losing it!

F=ma ALWAYS applies. I was taught in physics that if you're totally clueless on a
question you can always get partial credit for writing F=ma (or F=dp/dt if you really
need another point)

"The_navigator©" wrote in message
...
You tell me!

Cheers MC

Gerard Weatherby wrote:
On Wed, 23 Jul 2003 11:34:39 +1200, The_navigator© wrote:


But it's not accelerating -or is it?


Technically, that depends on your reference frame. Let's consider the earth
stationary and the rock stationary. Therefore it is not accelerating. Does F=ma
still apply?


S/V Cat's Meow
http://www.catsmeow.org