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Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 11:55 am
by Chris Smith
Time only comes into play when work is "put to action" but not when we store it. <p>Gas has stored energy in it and is measurable in BTUs per pound of fuel, and it is released by a motor over time. [work done] <p>That’s work, and time, yet the "equivalent" BTUs are stored in a liquid and only have a equivalent amount of BTU until they are used. <p>We divide up that work over a period of time so that we can have a measurement of the work over all for “number sake only”. It is not part of the Watt statment until it is "at work"<p> If you release a watt over a second of time, it is a watt second unit of energy. <p>If you store a watt's worth of energy, no time is involved. <p>This is why all the statements relating to the watt are as follows:<p>It is “equivalent” to one joule per second (1 J/s), <p>Your generator is measured by the same kilo watt rating as house hold consumption or power. It is rated by the hour. KWA

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 12:30 pm
by terri
Wal-K-TargMart has AA batteries on sale.

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 12:34 pm
by terri
(OK, OK, challenge me on "batteries" versus "cells." C'mon, c'mon, I dare ya... I double-dog-triple-dare ya. I'll fightcha with one paw tied behind my back. I'll fightcha on one foot, I'll fightcha with my eyes closed... C'mooooonnnn, c'monnnnnn!")<p>(Cf Bert Lahr as the Lion in Wizard of Oz.)

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 12:35 pm
by Will
Definitions seem to be dependent on the source? My definitons are Watts are units of Power. Power is the rate (In work/energy units per unit of time) of doing/consuming/generating work or energy. Energy units are Joules, Btu, ergs, Newton.Metres, ft.lbf etc. The term Watts per Second (W/s) has no practical meaning, the term Watt.Second is a unit of work or energy. The original discussion (tho not specified in such terms - it had a hint of perpetual energy production in it!) suggested to me the process of converting mechanical energy to electrical power. Hence One Watt = One Joule per Second = One Newton.metre per second. One kg = 9.806650000000. . . Newton, one foot = 0.304800000. . . metre and one pound (lbf) - 0.4535923700000. . kg which all results in 7.4 W approx = to 327.5 ft.lbf per second as per my original posting.
I think that some of the postings implied, not explicitly, that, if you could just get a 44 - 88 lbf. weight on your back oscillating up and down then you could get 7.4 W of power out of it without adding anything else in - Forget that ! - it would be perpetual motion again

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 1:18 pm
by Chris Smith
All of our units are labeled specifically for good reason. <p>Pounds/ feet [not foot pounds] becomes horse power WHEN we add in time. <p>It starts off as two dimensional, and gains a third dimension, and a new name. Horse power. <p>The pound has no relationship to time, nor does a foot measurement. <p>Mass sits still, and still has mass. <p>These are separate measurements as defined by their originators. <p>The watt is said to be “equivalent to” because the watt had a different origin. Although they named the unit after James Watt, he was busy with the Steam Engine and horse power. The watts origin came from the electrical unit of one amp and one ohm, but when this unit of energy or work is added up "with time", it becomes another figure or unit of work. That’s where the Joule and horsepower come in. Any energy equation is equivalent to another equation through the use of math.

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 7:44 pm
by rshayes
"Pounds/ feet [not foot pounds] becomes horse power WHEN we add in time."<p>1 horsepower = 550 foot-pounds/second. It has nothing to do with "pounds/foot". You do not "add in time". Power is the derivative of energy with respect to time. It can also be described as the rate of doing work. Differentiation was described by Newton and others by the end of the 1700's. It isn't exactly a new concept. <p>"The pound has no relationship to time, nor does a foot measurement."<p>Force is mass times accelleration (See Newton). A pound is the force needed to accellerate one slug of mass at a rate of one foot/second^2. The pound is not a unit of mass, but of force.<p>Both the joule and the watt are defined using mechanical standards.<p>1 joule = 1 meter^2-kilogram/second^2<p>1 watt = 1 meter^2-kilogram/second^3<p>I suspect that the volt, ohm, and ampere were chosen to make the electrical energy unit equal the mechanical energy unit. This could be done using calorimetric methods, and these were well established by the end of the 1800's. It would be an amazing coincidence if they matched up to better than 1 part in 1000 without any planning.

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 8:30 pm
by Chris Smith
There is no such thing as the “foot pound”.<p>It pounds-feet. [from my mechanical engineering days] <p>Energy stored or energy potential, has no time frame in it. <p>Watts,... is a potential.<p>Only Work or power involves the time frame units. <p>There is no statement of time in the description of what a watt is, there are comparisons, there are equivalents, there are cross references, and there are generalizations.<p>A watt can be released in a second, a minute or an hour, and thus only comparisons can be inferred as to the other time frames like the horse power or the joule. <p>watt
n 1: a unit of power "equal to" 1 joule per second; the power dissipated by a current of 1 ampere flowing across a resistance of 1 ohm [syn:<p> W] 2: Scottish engineer and inventor whose improvements in the steam engine led to its wide use in industry (1736-1819) [syn: Watt, James Watt]<p>Watt \Watt\, n. [From the distinguished mechanician and scientist, James Watt.] (Physics)

A unit of power or activity "equal to" 10^7 C.G.S. units of
power, or to work done at the rate of one joule a second. <p>An
English horse power is approximately equal to 746 watts.<p>Equal to is the key wording here. A gas tank full of gas has a potential full of BTUs. Depending on what engine it burns in is equal to its horse power released. <p>Burn ten gallons a minute, or burn one gallon an hour, its called "potential", and for a good reason.<p>[ September 10, 2005: Message edited by: Chris Smith ]</p>

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 8:49 pm
by Newz2000
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by stephen:
Power is the derivative of energy with respect to time. It can also be described as the rate of doing work.<hr></blockquote><p>blah. I hate calculus.<p>[ September 10, 2005: Message edited by: Matt Nuzum ]</p>

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 9:47 pm
by Chris Smith
The portable generator is properly rated as 3000 watts. There is no time dependence.<p>All generators are related to time, same as the household power system. <p>Watts from a generator are related to Watt hours and can be measured by any watt/ hour meter.<p>[ September 10, 2005: Message edited by: Chris Smith ]</p>

Re: Generate 7w of electricity by walking

Posted: Sat Sep 10, 2005 11:10 pm
by positronicle
--Edited by Positronicle--

Re: Generate 7w of electricity by walking

Posted: Sun Sep 11, 2005 3:55 am
by rshayes
"There is no such thing as the ?foot pound?.<p>It pounds-feet. [from my mechanical engineering days]"<p>Just offhand, I can find the term foot-pounds used in the following references:
1) The CRC Handbook of Chemistry and Physics,
2) Mark's Standard Handbook for Mechanical Engineers,
3) Reference Data for Radio Engineers,
4) Physics for Students of Science and Engineering (Halliday & Resnick)<p>"There is no statement of time in the description of what a watt is ..."<p>"watt
n 1: a unit of power "equal to" 1 joule per second; the power dissipated by a current of 1 ampere flowing across a resistance of 1 ohm [syn:"<p>A watt is one joule per second. That is certainly a statement of time.<p>"A watt can be released in a second, a minute or an hour..."<p>A watt is not a quantity of energy. It is the rate of transfer of energy.<p>
The NIST web site has a fair amount of information on the International System of Units. The basic units are the meter, kilogram, second, ampere, kelvin, mole, and candela. All of the other units, such as the joule, watt, volt, and ohm are derived units based on the seven basic units. The joule and watt are based on the meter, kilogram, and second.

Re: Generate 7w of electricity by walking

Posted: Sun Sep 11, 2005 12:02 pm
by Chris Smith
A watt is not one joule, it is "equal" to one joule. <p>Pounds feet is the proper engineering term, but some don’t learn their English or their engineering very well and call it foot pounds. <p>Nothing new there? <p>Much like the word “Equivalent” has its own following of mis readers. <p>Pounds feet is the proper term because the foot measurement does not change in the equation. <p>100 foot pounds implies 100 feet, over a pound of object.

100 pounds of weight on the other hand always is leveraged by the unchanging one foot, thus pounds feet is the proper term. <p>We have not only become a illiterate society, but one of illiterate engineers as well. <p>And were busy making excuses for being this way instead of learning the proper terms and ways. Yes, that is a path that leads to more ignorance.

Re: Generate 7w of electricity by walking

Posted: Sun Sep 11, 2005 2:07 pm
by Dean Huster
For joggers, I'd think that you could make a more comfortable and more productive generator using one of the trike pneumatic-wheeled baby strollers with the wheels geared to a generator (and not one of those lousy bicycle-light monstrosities, either!). Yes, it's only for a paved or lightly-graveled road and not rough hiking, but that's OK. The idea is to generator power in whatever you do so that you can take that generated power home and use it instead of the grid, thereby saving on our resources and reducing pollution. That baby stroller needs to have the wheel-driven generator, a solar panel on top and maybe a small wind-driven generator as well.<p>And what's all this Bow-Flex crap? The government should mandate that all exercise machines, instead of using weights, air brakes, friction, etc. should drive generators with batteries as the loads. If you're going to expend the energy, don't do it making frictional heat in an air-conditioned house! Other than dead-weight equipment, the generator should make an excellent resistance device for bikes, stair-steppers, rowers or whatever. In fact, George, on his rowing machine, could supply power for Margie's treadmill -- and give her some interesting surprises as well when he alters his pace!<p>We should be able in install generators in all of our waste plumbing to harness all that water (and whatever else) that we flush down the drain, driving little turbo-electric plants to charge batteries.<p>The door closer on the screen door could be an electromagnetic device that charges batteries. Heaven knows that a house with five kids could keep that one going a lot -- oh, wait a minute. It's 2005. All those kids are in their bedrooms playing video games.<p>For some of you younger folks, attaching a piston to the springs on your bed and driving a generator could probably generate enough power to get the morning coffee off to a good start.<p>Oh, the possibilities are just endless!!<p>Dean

Re: Generate 7w of electricity by walking

Posted: Sun Sep 11, 2005 2:29 pm
by Chris Smith
Imaging a heavy weight spring loaded in the back of your pick up?<p> Every time you hit a bump, half a ton could produce power into the other half ton of batteries, but the gas bill and brake pad bill would be a bitch.

Re: Generate 7w of electricity by walking

Posted: Sun Sep 11, 2005 4:15 pm
by Robert Reed
<p>[ September 11, 2005: Message edited by: ROBERT REED ]</p>