Externet

Thanks, gentlemen. The bow and arrow was chosen for the question instead of launching a ball by arm force because a force could be kind of measured to the string tension applied. About the frontal area, it is for a question like this, to consider all arrows identical in shape. J.C. indicates the smallest mass will achieve the highest velocity. I believe that; but what about the travel distance ? Back to the arm and ball throwing, A paper ball, a lead ball and a baseball -made all same size and aerodynamics- I can assure the baseball will fly much farther. Not the lightest nor the heaviest will reach farther. It will be the one that 'matches' the arm strenght. Now I would like to see that translated into calculations, with bow and arrow instead of arm and ball.

A bow string pushes an arrow say at 50N force for 0.05 seconds. If the arrow is made of lead, it will not reach very far. If the arrow is made of balsa wood, it will not reach very far. If the arrow has certain mass, will 'match' and will reach the farthest. How to calculate the optimal matching mass for an arrow in order to reach the farthest; for a given force / impetus ?

Hi. Cannot recommend which one would fit the best for you, but the one am most familiar with (Electronics Workbench) seems has been adquiered by National Instruments, as here : http://www.ni.com/white-paper/5662/en Old simpler/smaller/earlier versions as 5.12 may be scattered somewhere in the net, as here : http://computertraining2011.blogspot.com/2011/04/electronics-workbench-512-full-version.html There is many others, free and not; available from a search " circuit simulator "

Hi. As you are not an electronics guy, you must learn the basics in electronics and the way each component works and what it does and how it is used before jumping to microcontrollers as the Arduinos. Arduinos do nothing at all by themselves unless you tell them what, how, when... and that is dome with programming; something else you must learn before jumping to use Arduinos. I suggest you start with books, hands-on electronics tutorials abundant on the net and experimenter kits. Here is an example for what you will get into: ----> www.ardx.org/src/guide/2/ARDX-EG-SOLA-WEB.pdf If that is too much, better start from zero with books. Later, jump to ----> http://www.williamson-labs.com/ And you will see a veeeery long road in front of you for the field of electronics. The Arduino Uno can control up to 14 devices. ----> http://www.arduino.cc/

I just wanted a guess on what deposits to expect attached to the electrodes by electrolysis of a murky river carrying all sorts of minerals, using perhaps stainless steel anode and cathode plates; stepping trough different very regulated fixed voltages. And if -the electrochemical series list -or the galvanic series list, as in ---> http://en.wikipedia.org/wiki/Galvanic_series -or the standard electrode potential list as in ---> http://en.wikipedia.org/wiki/Standard_electrode_potential_%28data_page%29 applies in some form for the guess. Or if am way off from expressing properly what am asking.

Can anyone help fine tuning the process ? Am putting the beef steak with a couple of tablespoons of oil, salt and pepper, in a glass bowl with an upside up glass dish as a lid. Oil splatter falls back onto the steak that way, and no mess. It works nearly well at 70% power for a couple of minutes, not as good flavor as grilled of course, but perhaps some of you have perfected the task and suggest tweaks... Come on with something !

Charles: you are talking about another tree, mentioned in Genesis 2.17; the one that God lied about, as eating from it did not cause the sure death of Adam as promised; but not subject of this thread.

Hi. By applying 0.1 Volt to electrodes in a solution of multiple compounds, as a murky river; would only one or a few elements be collected ? If the voltage is increased to 0.2 V, would additional others join and get deposited ? Stepping up the voltage, would more and more elements attach to the electrodes ? Is that the way it works ? The metals or compounds being in minute nanoparticle concentrations, diluted or in suspension as in a river. Making the river to flow trough an electrolytic pipe internals, would such metals stick to electrodes placed inside the pipe ? Is that the way the electrochemical series would work in electrolysis, cumulatively selecting different metals depending of the voltage ? Am sorry about the poor terminology or attempt to express the question. In other words, would different voltages deposit different elements onto the electrodes ?

Thanks, imatfaal. A couple of things... - Referring to an English dictionary may not be a proper way to research if the word is not English in origin. Seems to me it is German or Latin in origin. - If such supposed movement from Roman citizens did succeed in fighting a particular 'then-potential' schism, there may have been no schism at all and not much records to research are left. Here is something from Italian source : http://it.wikipedia.org/wiki/Scisma just in case was a Roman citizens movement. The date the romanticism (as known) and not to be confused with 'romantic' started around 1770 from what I could find; and that coincides with some schism -or attempt of- by the Anglican church in the XVI century : ----> http://it.wikipedia.org/wiki/Chiesa_anglicana Later, from somewhere on the net : The date of the 'great schism' 1054 I wrote in the original post was a guess of the most important one, but may have been another one a long time later. Sorry, English is my third language and cannot grab the meaning of your "he was on the wind up" Thanks.

It has been about fifty years with the teachings of a wise catholic priest, admirable history and literature professor embedded in my 'retina' He mentioned the romanticism originated as a movement of Roman citizens against the church schism. That is, -----> Rome anti schism. (1054?) Can anyone clarify, deny or leave open door to such origin of the movement/word ? I was never able to confirm such anywhere. --------------------------------------------------------------------------------------------------- Llevo unos cincuenta años con la enseñanza de un culto sacerdote católico profesor de historia y literatura grabados en mi 'retina'. Mencionó que el romanticismo se originó como un movimiento de ciudadanos de Roma en contra del cisma de la Iglesia. ¿Hay alguien que pueda aclarar, negar o dejar puerta abierta a tal aseveración de Roma-anti-cisma ? Nunca pude encontrar o confirmar tal relación. ¿ Alguien lo sabe ? ---------------------------------------------------------------------------------------------------

As mentioned on Genesis 4.17, the wife of Cain ?

What does "the land of Nod" mean as mentioned on Genesis 4.16 ?

Such "tree of life" is mentioned in Genesis 3.22. What is it ?

It was made around 25¿? years ago. I remember reading but not much more details than being about 50cm diameter and made of glass, as thin as a soap bubble.

Hi all. Is there in the world a nation, tribe, ethnicity... with no content of religion in their beliefs/activities ? No scriptures, commandments, rites... ?

Nasa did bring back to earth asteroid particles on the Stardust spacecraft on January 2006. Check the cost of the mission, multiply it by a number, to capture larger ones. ----> http://en.wikipedia.org/wiki/File:Stardust_Capsule_on_Ground.jpg ----> http://en.wikipedia.org/wiki/File:Aerogel_labtest.jpg The problem is to stop the asteroid speed to zero relative to earth in order to 'drop it' with a parachute for soft landing.

A sailboat keel has a roundish leading edge and a somewhat sharp trailing edge. If both edges are made as sharp as a razor blade, setting aside the fragility of such edges; will the sharper keel have less drag ?

Hi. I learned somewhere that sun radiation (heat + light) passes trough glass as in a window, but the heat does not escape again towards the outside trough the glass, bouncing back and getting trapped indoors as in a greenhouse. I have trouble understanding the effect; does it mean an item enclosed in a glass jar indoors will not get warm as the heat will not pass trough glass again ? (except the amount of heat transferred by convection from room air to jar)

Hi. The temperature of the air along the path of a lightning bolt rises to many hundreds of degrees in about a tenth of a second; is that correct ?

Hi. Would you please let me know what dyes that you know are commonly used in households and industry ? (Not pigment particles in suspension) I can think of clothes dyes, hair dyes, fountain pen inks, food dyes. Others please ?

Those clever experiments developed by scientists along the years, as light spectrum on a prism, resonances, beam interruption wheels, mercury barometer column, magnetic induction, Millikan's, and many other share great lucidity in their conceptions. How would you design a clever experiment to measure the propagation speed of gravity ?

Hi. Passing an electric current, even for a brief second, has devastating effects on living cells, destroying/killing them. If a person has a topical infection, would applying electrical current confined to a short path within the affected area with reduced/minimal effect to healthy surrounding tissues work ? Does topical anesthesia work for minor electroshocks ? Does healthy skin, muscle cells killed in an electroshock get replaced by new growth ? Electrodes placement would need some thoughtful technique, but nothing seems extraordinary there. Thanks for opinions. -Please move post to proper section of the forum if this is not the correct one-

Finally found, resurrected this post to let know if someone has interest. Thanks. ----> http://jordanbunker.com/archives/41

From .net to .com ---> http://scienceforums.com/

The reverse of a river boat, being the river flow turning the paddle wheel of an anchored boat. How many horsepower would yield a 0.5m/s say-laminar river flow, for 1 m^2 submerged paddles ? Just a pictorial---> http://njscuba.net/zzz_artifacts/paddlewheel.jpg (not homework)