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Natural Science Forum / Physics / General Physics / February 2007A few silly questions
Hello folks, I'm engaging in discussion with someone and have found myself going around in circles, so I'd appreciate some help with a few mundane questions: Can velocity change without time? Can acceleration take place without time? Is there such a thing as instant acceleration? Can momentum change without time? Can anything change without time? Is this statement true: "But when no distance is covered against or with the force, no work is done and energy is neither stored nor expended."? Thanks for your time.  SignatureAKA "Dobbie The House Elf" > Hello folks, > > I'm engaging in discussion with someone and have found myself going around > in circles, so I'd appreciate some help with a few mundane questions: > > Can velocity change without time? Velocity is defined as the derivative of position with respect to time. http://scienceworld.wolfram.com/physics/Velocity.html > Can acceleration take place without time? Acceleration is *defined* as the derivative of position with respect to time. http://scienceworld.wolfram.com/physics/Acceleration.html > Is there such a thing as instant acceleration? Acceleration at any point in time has a value. > Can momentum change without time? Conservation of Momentum http://scienceworld.wolfram.com/physics/ConservationofMomentum.html > Can anything change without time? No > Is this statement true: "But when no distance is covered against or with the > force, no work is done > and energy is neither stored nor expended."? Work http://scienceworld.wolfram.com/physics/Work.html > Thanks for your time. >> Hello folks, >> [quoted text clipped - 12 lines] > to time. > http://scienceworld.wolfram.com/physics/Acceleration.html CORRECTION Acceleration is *defined* as the derivative of *velocity* with respect to time. http://scienceworld.wolfram.com/physics/Acceleration.html >> Is there such a thing as instant acceleration? > [quoted text clipped - 17 lines] > >> Thanks for your time. > >> Hello folks, > >> [quoted text clipped - 17 lines] > to time. > http://scienceworld.wolfram.com/physics/Acceleration.html Acceleration is the second dervative of position with respect to time. > >> Is there such a thing as instant acceleration? > > > > Acceleration at any point in time has a value. A third derivative is called a 'jerk'. Maybe he means the infinith derivative of position with respect to time?? > >> Can momentum change without time? > > [quoted text clipped - 3 lines] > >> Can anything change without time? > > No I would say "no" as far as measurability is concerned. The notion of "information" is too abstract to attach to time since the concept of simultaneity is understood. > >> Is this statement true: "But when no distance is covered against or > >> with the force, no work is done and energy is neither stored nor expended."? [quoted text clipped - 3 lines] > > > >> Thanks for your time. > > Hello folks, > > [quoted text clipped - 29 lines] > Work > http://scienceworld.wolfram.com/physics/Work.html Thanks for the links. By the way, I'm not just asking these questions because I'm too lazy to do any study, but that without any outside input, I get the feeling that the person I'm arguing with feels at liberty to call anything I say, wrong, regardless of its merits. SignatureAKA "Dobbie The House Elf" >By the way, I'm not just asking these questions >because I'm too lazy to do any study, but that without any outside input, I >get the feeling that the person I'm arguing with feels at liberty to call >anything I say, wrong, regardless of its merits. We get a few of those in here. >> By the way, I'm not just asking these questions >> because I'm too lazy to do any study, but that without any outside >> input, I get the feeling that the person I'm arguing with feels at >> liberty to call anything I say, wrong, regardless of its merits. > > We get a few of those in here. Unfortunately, Mr. Dobson is one of them. He only came here looking for "ammo." I'm the person he was arguing with. The context was from his claim that, in the case of a falling body brought to a stop by a cord (as in a hanging), "considering only those two factors [height and weight], the forces involved are very predictable." I immediately pointed out that those two factors don't define the problem, let alone lead to "very predictable" forces. Given only those two factors, the only thing that can really be said is 0 < F < infinity. And since F here is magnitude rather than vector force, that's really no restriction at all. When we went around on this, the infinite force limit was brought up and Mr. Dobson said that of course that would require infinite energy (or words to that effect). Which I disputed since, yes, you would have infinite force, but, since (by the initial stipulation of the condition), it would take place over zero distance. infinity * zero, undefined but possibly meaningful if considered as a limit. (In this case, the limit should come to simply the kinetic energy of the falling body--not the "infinite energy" Mr. Dobson claimed.) This, of course, leaves aside that stopping a moving body in a particular frame doesn't require energy. Rather it gives up energy whether it's used to move something else or is given up as heat, breaking things, whatever. Several times over the course of the discussion I pointed out that the infinite force--where the time over which it is applied and, by extention, the distance over which it is applied, is zero--was the case "at the limit." Likewise the F=0 end (where the distance over which it is applied would be zero. These were only cited as the extreme cases, the limits, which illustrate why the claim of "forces are very predictable" is incorrect. And, at the limit (speaking purely mathematically) there is no prohibition on having a change in velocity/momentum occur in zero time. All you've done is specify a point in the position/time curve where the curve is continuous but at which the first and all subsequent derivatives does not exist. Well, eventually, he finally got around to claiming that he actually meant to include those other factors necessary to define the problem and we should just try to forget that he spent considerable time trying to defend the original proposition, as originally worded. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>> By the way, I'm not just asking these questions >>> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 5 lines] > Unfortunately, Mr. Dobson is one of them. He only came here looking for > "ammo." If you call education "ammo" then I can spare some. > I'm the person he was arguing with. The context was from his claim that, in > the case of a falling body brought to a stop by a cord (as in a hanging), [quoted text clipped - 4 lines] > F < infinity. And since F here is magnitude rather than vector force, > that's really no restriction at all. Pity they didn't rip Saddam Hussein's head off too, you mean? Seems to me that the amount a rope or a neck stretches before it breaks decides the outcome, otherwise it's a bungee jump. I'd say the force involved was predictable or people wouldn't bungee jump. > When we went around on this, the infinite force limit was brought up and Mr. > Dobson said that of course that would require infinite energy (or words to > that effect). He's not Mr. Dobson, he's Dobby the House Elf. Be respectful of his chosen name. The force will not be infinite, the rope or the neck will break. > Which I disputed since, yes, you would have infinite force, > but, since (by the initial stipulation of the condition), it would take > place over zero distance. infinity * zero, undefined but possibly > meaningful if considered as a limit. I get the feeling that the person Dobby was arguing with feels at liberty to call anything Dobby says, wrong, regardless of its merits, because the argumentative fuckheaded muggle brought infinity into the argument in the first place. *plonk* >>>> By the way, I'm not just asking these questions >>>> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 7 lines] > > If you call education "ammo" then I can spare some. If he ever actually showed any evidence of learning anything, that would be a valid point. >> I'm the person he was arguing with. The context was from his claim >> that, in [quoted text clipped - 16 lines] > I'd say the force involved was predictable or people wouldn't > bungee jump. How much the rope or neck stretches. How much soft tissues sag. How much the body rotates. Within broad limits, predictable. But not so predictable that even experienced executioners did not get the occassional hanging failure of both types--failure to break the neck or decapitation. >> When we went around on this, the infinite force limit was brought up >> and Mr. [quoted text clipped - 4 lines] > He's not Mr. Dobson, he's Dobby the House Elf. Be respectful > of his chosen name. Go read some of his posts in rec.martial-arts and then come talk to me about being respectful. > The force will not be infinite, the rope or the neck will break. Had he said that, I would have had no problem with it. But that's not the argument he made. Instead, he was the one making the argument about infinite energy being required. >> Which I disputed since, yes, you would have infinite force, >> but, since (by the initial stipulation of the condition), it would [quoted text clipped - 4 lines] > I get the feeling that the person Dobby was arguing with feels at > liberty to call anything Dobby says, wrong, regardless of its merits, You get the feeling wrong. > because the argumentative fuckheaded muggle brought infinity into > the argument in the first place. And, of course, everybody knows scientists and mathmaticians _never_ use infinity as one limit of an open interval. > *plonk* SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > > Pity they didn't rip Saddam Hussein's head off too, you mean? > > Seems to me that the amount a rope or a neck stretches before it [quoted text clipped - 6 lines] > > Within broad limits, predictable. Yeah, that's what I said, predictable. Would you like some more salt for that wound, sir? > But not so predictable that even > experienced executioners did not get the occassional hanging failure of both > types--failure to break the neck or decapitation. Staw man. I said that I didn't think that even experienced hangmen could be expected to achieve a zero failure rate. In any case, the argument was over what was the cause was of those few failures, not if a few failures were to be expected. > >> When we went around on this, the infinite force limit was brought up > >> and Mr. [quoted text clipped - 7 lines] > Go read some of his posts in rec.martial-arts and then come talk to me > about being respectful. Oh, poor soul. > > The force will not be infinite, the rope or the neck will break. > > Had he said that, I would have had no problem with it. But that's not > the argument he made. Instead, he was the one making the argument about > infinite energy being required. It was a throw-away comment, not even relevant and long ago recanted. But you continue to flog that dead horse, as you have little other than your pettiness to fall back on. > >> Which I disputed since, yes, you would have infinite force, > >> but, since (by the initial stipulation of the condition), it would [quoted text clipped - 6 lines] > > You get the feeling wrong. Another strong argument. > > because the argumentative fuckheaded muggle brought infinity into > > the argument in the first place. > > And, of course, everybody knows scientists and mathmaticians _never_ use > infinity as one limit of an open interval. And scientists don't use controlled experients, as the results are too far removed from reality to be useful. SignatureAKA "Dobbie The House Elf" >> > Pity they didn't rip Saddam Hussein's head off too, you mean? >> > Seems to me that the amount a rope or a neck stretches before it [quoted text clipped - 66 lines] > And scientists don't use controlled experients, as the results are too far > removed from reality to be useful. He's all yours, enjoy your practice. I've dumped the unworthy muggle as a no contest lightweight. He seems to have missed the *plonk* by replying. Not too smart, that. >He's all yours, enjoy your practice. I've dumped the unworthy muggle >as a no contest lightweight. He seems to have missed the *plonk* >by replying. Not too smart, that. Yeah, been saying that. He thinks collecting dots makes a person intelligent, never mind whether or not you're able to connect them. SignatureAKA "Dobbie The House Elf" >> He's all yours, enjoy your practice. I've dumped the unworthy muggle >> as a no contest lightweight. He seems to have missed the *plonk* >> by replying. Not too smart, that. > > Yeah, been saying that. He thinks collecting dots makes a person > intelligent, never mind whether or not you're able to connect them. Whereas you think that simply repeating incorrect "facts" with strongly, with conviction, and tossing insults at the people who try to correct your errors makes you "right." SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > He's all yours, enjoy your practice. I've dumped the unworthy muggle > as a no contest lightweight. That's a clever way to say you ran away, puppy. >He seems to have missed the *plonk* > by replying. Ooh, he didn't recognize your stupidity. Puppies can pretend they are big dogs all day long, but at the end of the day, they scamper. -Mike K. > He's all yours, enjoy your practice. I've dumped the unworthy muggle > as a no contest lightweight. He seems to have missed the *plonk* > by replying. Not too smart, that. Ohh, and by the way.... *plonk*. -Mike K >> I'm the person he was arguing with. The context was from his claim that, in >> the case of a falling body brought to a stop by a cord (as in a hanging), [quoted text clipped - 4 lines] >> F < infinity. And since F here is magnitude rather than vector force, >> that's really no restriction at all. >Pity they didn't rip Saddam Hussein's head off too, you mean? >Seems to me that the amount a rope or a neck stretches before it >breaks decides the outcome, otherwise it's a bungee jump. > I'd say the force involved was predictable or people wouldn't >bungee jump. You mean bungee jumpers don't die randomly? Let me make a note. Hahaha... >> When we went around on this, the infinite force limit was brought up and Mr. >> Dobson said that of course that would require infinite energy (or words to >> that effect). >He's not Mr. Dobson, he's Dobby the House Elf. Be respectful >of his chosen name. >The force will not be infinite, the rope or the neck will break. Hahaha... There you go. I keep telling them, but they won't listen. Hahaha... >> Which I disputed since, yes, you would have infinite force, >> but, since (by the initial stipulation of the condition), it would take >> place over zero distance. infinity * zero, undefined but possibly >> meaningful if considered as a limit. >I get the feeling that the person Dobby was arguing with feels at >liberty to call anything Dobby says, wrong, regardless of its merits, >because the argumentative fuckheaded muggle brought infinity into >the argument in the first place. > >*plonk* Ouch! That's gotta hurt. Hahaha... SignatureAKA "Dobbie The House Elf" >>> I'm the person he was arguing with. The context was from his claim that, > in [quoted text clipped - 15 lines] > > You mean bungee jumpers don't die randomly? Let me make a note. Hahaha... That's the heart attack when the epinephrine gets going, not the bungee breaking... but they DO break, and then it is the almost instantaneous acceleration when the ground comes up and taps you on the head, not the neck stretching. No prediction is totally foolproof. >>> When we went around on this, the infinite force limit was brought up and > Mr. [quoted text clipped - 22 lines] > > Ouch! That's gotta hurt. Hahaha... If I didn't plonk the muggles I'd never find a student, but I do have to keep some muggles back for my own amusement. Now, Dobbie, find me a theoretically rigid rod and accelerate it with a hammer striking one end. I want to know when the other end begins to move. >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message news:6i4Bh.281230$QY6.37646@fe1.news.blueyonder.co.uk... >>>"David L. Burkhead" <dburkhead@sff.net> wrote in message > [quoted text clipped - 10 lines] >acceleration when the ground comes up and taps you on the head, >not the neck stretching. No prediction is totally foolproof. Sure, but I don't see jumpers dying without any explanation, as you would expect, in David's world. The few deaths that I've heard of where due to such silliness as not securing the rope properly, or the rope being too long, or picking the wrong type of rope, just basically down to stupidity. I think I heard of one where the rope was securely tied to the jumper's boots. The boots survived, the jumper didn't. Hahaha... >>I get the feeling that the person Dobby was arguing with feels at >>liberty to call anything Dobby says, wrong, regardless of its merits, [quoted text clipped - 11 lines] >it with a hammer striking one end. >I want to know when the other end begins to move. Both ends move in unison. SignatureAKA "Dobbie The House Elf" > >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message > news:6i4Bh.281230$QY6.37646@fe1.news.blueyonder.co.uk... [quoted text clipped - 17 lines] > Sure, but I don't see jumpers dying without any explanation, as you would > expect, in David's world. Straw man. > The few deaths that I've heard of where due to > such silliness as not securing the rope properly, or the rope being too > long, or picking the wrong type of rope, just basically down to stupidity. "Rope being too long" IOW, it stretched long enough that they hit the ground. Now, why did it do that? You do know that how much the bungee cord stretches, and the forces applied to it, interrelate don't you. IOW, they didn't predict the force right. > I think I heard of one where the rope was securely tied to the jumper's > boots. The boots survived, the jumper didn't. Hahaha... [quoted text clipped - 16 lines] > > Both ends move in unison. Now reconcile that with Special Relativity (do you even know why SR and rigid rods come up together?) Perfectly rigid objects are a violation of some pretty basic physics. Which is why I said, from the beginning, that the reason you can't actually achieve infinite acceleration/force in reality is that there are no perfectly rigid objects. (Furthermore, although I didn't say it at the time, they not only don't exist, they cannot exist.) Missing points like that, and their implication, is why you consistently misrepresent my position. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > > >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message > > news:6i4Bh.281230$QY6.37646@fe1.news.blueyonder.co.uk... [quoted text clipped - 62 lines] > Missing points like that, and their implication, is why you consistently > misrepresent my position. > >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message > news:6i4Bh.281230$QY6.37646@fe1.news.blueyonder.co.uk... [quoted text clipped - 39 lines] > > Both ends move in unison. I thought you might say that, but there are serious theoretical difficulties with your proposal. According to the muggle magician Einstein, nothing can travel faster than light; and nor have I specified the length of the rod. In his book of magic spells he writes: "The theory to be developed is based--like all electrodynamics--on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (systems of co-ordinates), clocks, and electromagnetic processes. Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters." --Einstein. reference: http://www.fourmilab.ch/etexts/einstein/specrel/www/ Thus if a theoretically rigid magic wand were to reach between two observers who are some miles apart, each can signal the other faster than light by tapping on the magic want in Morse code (you have to say "observer" in physics newsgroups). Morse was a digital code used before ASCII. So the conclusion is rigid magic wands and rods transmit signals faster than optical fibres. "Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters." --Einstein. So Dobbie, I want you to send a muggle (any muggle) to find me a rigid magic wand, I already have a hammer. Would a kindly house elf mind doing that for a poor old sorcerer? Or maybe we could use my hammer to knock some sense into the muggles' wooden heads? > So Dobbie, I want you to send a muggle (any muggle) to find me a > rigid magic wand, I already have a hammer. Would a kindly house elf > mind doing that for a poor old sorcerer? > Or maybe we could use my hammer to knock some sense into the muggles' > wooden heads? You really don't say anything do you puppy? No math or physics anywhere, Just stirring up dust. Dust that has already been acknowledged by the very source you claim to disprove. Will you be showing up in April, as a registered attendee? -Mike K. P.S. figure it out ... > >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message > news:6i4Bh.281230$QY6.37646@fe1.news.blueyonder.co.uk... [quoted text clipped - 39 lines] > > Both ends move in unison. I thought you might say that, but there are serious theoretical difficulties with your proposal. According to the muggle magician Einstein, nothing can travel faster than light; and nor have I specified the length of the rod. In his book of magic spells he writes: "The theory to be developed is based--like all electrodynamics--on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (systems of co-ordinates), clocks, and electromagnetic processes. Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters." --Einstein. reference: http://www.fourmilab.ch/etexts/einstein/specrel/www/ Thus if a theoretically rigid magic wand were to reach between two observers who are some miles apart, each can signal the other faster than light by tapping on the magic want in Morse code (you have to say "observer" in physics newsgroups). Morse was a digital code used before ASCII. So the conclusion is rigid magic wands and rods transmit signals faster than optical fibres. "Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters." --Einstein. So Dobbie, I want you to send a muggle (any muggle) to find me a rigid magic wand, I already have a hammer. Would a kindly house elf mind doing that for a poor old sorcerer? Or maybe we could use my hammer to knock some sense into the muggles' wooden heads? >>Now, Dobbie, find me a theoretically rigid rod and accelerate >>it with a hammer striking one end. [quoted text clipped - 18 lines] >reference: > http://www.fourmilab.ch/etexts/einstein/specrel/www/ >Thus if a theoretically rigid magic wand were to reach between two >observers who are some miles apart, each can signal the other faster [quoted text clipped - 3 lines] >So the conclusion is rigid magic wands and rods transmit signals >faster than optical fibres. Naturally, at the limit, sound travels faster than light does in a vacuum. Burkhead says so. >>"Insufficient consideration of this circumstance lies at the root of the >>difficulties which the electrodynamics of >>moving bodies at present [quoted text clipped - 5 lines] >Or maybe we could use my hammer to knock some sense into the muggles' >wooden heads? I know of a nincompoop with a theorectically rigid rod, on paper. Therefore, he thinks such a thing exists. Would that do? SignatureAKA "Dobbie The House Elf" >>> Now, Dobbie, find me a theoretically rigid rod and accelerate >>> it with a hammer striking one end. [quoted text clipped - 30 lines] > Naturally, at the limit, sound travels faster than light does in a > vacuum. Burkhead says so. Cite. You just demonstrate that you don't know what the phrase "at the limit" means, nor comprehend anything that I have actually said. >>> "Insufficient consideration of this circumstance lies at the root >>> of the difficulties which the electrodynamics of >>moving bodies at [quoted text clipped - 8 lines] > I know of a nincompoop with a theorectically rigid rod, on paper. > Therefore, he thinks such a thing exists. Would that do? Yawn. In your haste to get your dig in, you blatantly lie about my position. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>>Now, Dobbie, find me a theoretically rigid rod and accelerate >>>it with a hammer striking one end. [quoted text clipped - 29 lines] > Naturally, at the limit, sound travels faster than light does in a vacuum. > Burkhead says so. You seem to have a fixation with this troll Burkhead. >>>"Insufficient consideration of this circumstance lies at the root of the >>>difficulties which the electrodynamics of >>moving bodies at present [quoted text clipped - 8 lines] > I know of a nincompoop with a theorectically rigid rod, on paper. > Therefore, he thinks such a thing exists. Would that do? Is his name Einstein? Burkhead's theories are ignored by all. >>> I'm the person he was arguing with. The context was from his claim >>> that, in the case of a falling body brought to a stop by a cord (as [quoted text clipped - 14 lines] > You mean bungee jumpers don't die randomly? Let me make a note. > Hahaha... You might want to check the mortality statistics on bungee jumping. (Hint, it's not 100% safe.) >>> When we went around on this, the infinite force limit was brought >>> up and Mr. Dobson said that of course that would require infinite [quoted text clipped - 6 lines] > Hahaha... There you go. I keep telling them, but they won't listen. > Hahaha... How soon they forget. You might want to look up who it was who said "the actual limit preventing reaching infinite force is that there are no perfectly rigid ropes and other bodies, not this 'infinite energy' nonsense" or words to that effect. (Hint: it was the person _arguing_ with you.) >>> Which I disputed since, yes, you would have infinite force, >>> but, since (by the initial stipulation of the condition), it would [quoted text clipped - 9 lines] > > Ouch! That's gotta hurt. Hahaha... Plonked by a usenet kook. Yawn. I see sci-physics is as infested with them as when I used to hang here regularly. BTW, whatever happened to Alexander Abian and Ludwig/Archimedes Plutonium? SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > >>> I'm the person he was arguing with. The context was from his claim > >>> that, in the case of a falling body brought to a stop by a cord (as [quoted text clipped - 30 lines] > > How soon they forget. You might want to look up who it was who said > "the actual limit preventing reaching infinite force is that there are no > perfectly rigid ropes and other bodies, not this 'infinite energy' nonsense" [quoted text clipped - 15 lines] > > Plonked by a usenet kook. Yawn. That's very creative of you. Nice variation. Over at RMA, anyone who argues with a member of formally dominant clique is a troll, now you come in here calling anyone who doesn't agree with your bullshit, a kook. No-one can accuse you of lacking imagination. > I see sci-physics is as infested with them as when I used to hang here > regularly. BTW, whatever happened to Alexander Abian and Ludwig/Archimedes > Plutonium? Would that be sour grapes, as you got booted out? SignatureAKA "Dobbie The House Elf" > > >>> I'm the person he was arguing with. The context was from his claim > > >>> that, in the case of a falling body brought to a stop by a cord (as [quoted text clipped - 56 lines] > here calling anyone who doesn't agree with your bullshit, a kook. No-one > can accuse you of lacking imagination. Some quotes from Mr. Androcles: "Now, some people appear to insist that energy cannot be negative, but I explained why it could be. I didn't claim that mass could be negative, though. E = m(-c)^2 " What's the sign of the square of a negative number? "He forgot, GR predicts nothing at all." I guess the entire physics community is too stupid to realize that <fe-y>. "This one. Number 4, here: http://mathworld.wolfram.com/VectorSpace.html You cannot "rotate" mass or length into time and call it physics or mathematics. It is called 'lunacy'. Minkowski was a 'lunatic'. You don't have any ideas of your own but I'm certain those you've borrowed are 'psychotic'. " And here we see how any physics, no matter how conventional and well accepted within the physics community, is simply dismissed in the most derisive of terms. This is your "support." > > I see sci-physics is as infested with them as when I used to hang here > > regularly. BTW, whatever happened to Alexander Abian and > Ludwig/Archimedes > > Plutonium? > > Would that be sour grapes, as you got booted out? Very weak since it's kind of hard to be "booted out" of an open newsgroup. Really, go look up Alexander Abian and Ludwig/Archimedes Plutonium, long time regulars of sci.physics. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays <Big Snip> > And here we see how any physics, no matter how conventional and well > accepted within the physics community, is simply dismissed in the most > derisive of terms. > > This is your "support." Yeah, someone who thinks for himself. I like to think of myself somewhat the same. I don't care how much support there is for a thing, if I see that there's no sense in it. >> > I see sci-physics is as infested with them as when I used to hang > here [quoted text clipped - 6 lines] > Very weak since it's kind of hard to be "booted out" of an open > newsgroup. You managed it. How hard can it be? > Really, go look up Alexander Abian and Ludwig/Archimedes Plutonium, > long > time regulars of sci.physics. I don't see that looking them up could be of any benefit to me. SignatureAKA "Dobbie The House Elf" > <Big Snip> > [quoted text clipped - 5 lines] > > Yeah, someone who thinks for himself. If you really think that dismissing everything that has been learned over the course of several centuries qualifies as thinking for oneself, then there's little anyone can do to help you. > I like to think of myself > somewhat the same. Oh, you succeed most handsomely. The ability to completely ignore what's known and what folk have learned and to let your arrogance prevent you from actually learning anything is something you have in spades. > I don't care how much support there is for a > thing, if I see that there's no sense in it. The trouble is, you don't know enough about the subject to know if there's "sense" in it. You fail to realize that reality is under no obligation to make sense to you. >>>> I see sci-physics is as infested with them as when I used to >>>> hang here regularly. BTW, whatever happened to Alexander Abian [quoted text clipped - 6 lines] > > You managed it. How hard can it be? Only in your fever-induced delerium. >> Really, go look up Alexander Abian and Ludwig/Archimedes >> Plutonium, long >> time regulars of sci.physics. > > I don't see that looking them up could be of any benefit to me. Actually, probably none since you have repeatedly demonstrated a complete lack of ability to learn. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >> <Big Snip> >> [quoted text clipped - 10 lines] > then > there's little anyone can do to help you. Straw man. >> I like to think of myself >> somewhat the same. > > Oh, you succeed most handsomely. Naturally. > The ability to completely ignore what's known and what folk have learned > and to let your arrogance prevent > you from actually learning anything is something you have in spades. What do you mean by "known"? >> I don't care how much support there is for a >> thing, if I see that there's no sense in it. > > The trouble is, you don't know enough about the subject to know if > there's "sense" in it. You fail to realize that reality is under no > obligation to make sense to you. I know enough about reason to recognise contradictions. >>>>> I see sci-physics is as infested with them as when I used to >>>>> hang here regularly. BTW, whatever happened to Alexander Abian [quoted text clipped - 17 lines] > Actually, probably none since you have repeatedly demonstrated a > complete lack of ability to learn. Parrots demonstrate an ability to learn, also. SignatureAKA "Dobbie The House Elf" >>> <Big Snip> >>> [quoted text clipped - 12 lines] > > Straw man. Um, no actually since that's _exactly_ what your "supporter" has done. >>> I like to think of myself >>> somewhat the same. [quoted text clipped - 8 lines] > > What do you mean by "known"? Try picking up a physics book sometime, or talking to somebody who actually knows the subject. >>> I don't care how much support there is for a >>> thing, if I see that there's no sense in it. [quoted text clipped - 4 lines] > > I know enough about reason to recognise contradictions. No. You don't. You imagine contraditions where they are convenient to what you want to believe. >>>>>> I see sci-physics is as infested with them as when I used to >>>>>> hang here regularly. BTW, whatever happened to Alexander Abian [quoted text clipped - 19 lines] > > Parrots demonstrate an ability to learn, also. Which puts them one up on you. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>> If you really think that dismissing everything that has been >>> learned over the course of several centuries qualifies as thinking [quoted text clipped - 4 lines] > > Um, no actually since that's _exactly_ what your "supporter" has done. You're a fool and a liar. He has forwarded views that are completely mainstream, as well as stating where his views diverge from the norm. I think that is a sign of intelligence. Your tendency to swallow everything you're fed, is a major sign of stupidity. >>>> I like to think of myself >>>> somewhat the same. [quoted text clipped - 11 lines] > Try picking up a physics book sometime, or talking to somebody who > actually knows the subject. A tendency towards uttering non-falsifiable statements is a sign of a lack substance. >>>> I don't care how much support there is for a >>>> thing, if I see that there's no sense in it. [quoted text clipped - 7 lines] > No. You don't. You imagine contraditions where they are convenient to > what you want to believe. Again, non-falsifiable. >>>> I don't see that looking them up could be of any benefit to me. >>> [quoted text clipped - 4 lines] > > Which puts them one up on you. If I were you, I'd put away the thought of making a living as a comedienne; you're not funny. It might work out for you, as a clown, though. SignatureAKA "Dobbie The House Elf" >>>> If you really think that dismissing everything that has been >>>> learned over the course of several centuries qualifies as thinking [quoted text clipped - 8 lines] > You're a fool and a liar. He has forwarded views that are completely > mainstream, as well as stating where his views diverge from the norm. You haven't read any of his posts, have you, except those that "support" you. > I think that is a sign of intelligence. Your tendency to swallow > everything you're fed, is a major sign of stupidity. The tendency to believe that one is right and everyone else, in the same field, is not only wrong but stupid and insane is a major sign of megalomania. You have it. Your fellow Harry Potter fetishist has it. >>>>> I like to think of myself >>>>> somewhat the same. [quoted text clipped - 15 lines] > A tendency towards uttering non-falsifiable statements is a sign of a > lack substance. Without a common frame of reference it is impossible to have a meaningful dialog on the subject. You don't know enough to even understand the answer. Until you actually learn something about the subject you don't have the tools to understand the answer. >>>>> I don't care how much support there is for a >>>>> thing, if I see that there's no sense in it. [quoted text clipped - 9 lines] > > Again, non-falsifiable. Only in your own delusions. >>>>> I don't see that looking them up could be of any benefit to me. >>>> [quoted text clipped - 8 lines] > comedienne; you're not funny. It might work out for you, as a clown, > though. Hit a nerve, did I? SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > >> By the way, I'm not just asking these questions > >> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 14 lines] > F < infinity. And since F here is magnitude rather than vector force, > that's really no restriction at all. But we could do a ballpark estimate. It would be based on assuming purely vertical forces, an estimate of the thickness of the rope used and a guess as to its material (these lead to an estimate of the spring constant). From an estimate of the spring constant you would be able to work out the stopping distance and time. And as you say, the stopping distance or time for a given momentum is what tells you the force involved in that stopping. Specifically, F = dp/dt. You can also work it out in terms of energy and distance: work = integral(F*x dx) = 0.5*mv^2. If you are driving a car at 60 mph, you can stop in a long distance and time, as you do when you press the brakes, or you can stop in a short distance and time, as you do when you hit a wall. The forces in the second case are higher. [snip remainder of argument] - Randy >>>> By the way, I'm not just asking these questions >>>> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 22 lines] > spring constant you would be able to work out the stopping > distance and time. IOW, considering much more than just those two factors. And had Mr. Dobson simply said that, rather than arguing, for some time, about only those two factors being required, I would have had no problem with it. I also suspect that rotation would play a big part of it as well. If one reaches the end of the drop with the body hanging vertically, or at some angle, you'll get different force results. In fact, I suspect that's #3 in the list: height, weight, angle and rotation at end of drop. > And as you say, the stopping distance or time for a given > momentum is what tells you the force involved in that stopping. [quoted text clipped - 5 lines] > or you can stop in a short distance and time, as you do when > you hit a wall. The forces in the second case are higher. Well, yeah. Same speed (derived from drop height in the original equation) and mass/weight. Very different forces depending on other factors. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > >> By the way, I'm not just asking these questions > >> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 5 lines] > Unfortunately, Mr. Dobson is one of them. He only came here looking for > "ammo." How come I didn't fire it, then? > I'm the person he was arguing with. The context was from his claim that, in > the case of a falling body brought to a stop by a cord (as in a hanging), [quoted text clipped - 11 lines] > place over zero distance. infinity * zero, undefined but possibly > meaningful if considered as a limit. You said it was something which occured, which I disputed and you maintained. The conditions set out under the limit that you are speaking of do not occur, except as a concept. The argument was about reality, yet you flit back and forth between theoretical concepts and reality - without warning, so as to cause confusion. > (In this case, the limit should come to > simply the kinetic energy of the falling body--not the "infinite energy" Mr. > Dobson claimed.) This, of course, leaves aside that stopping a moving body > in a particular frame doesn't require energy. If you were to stop the moving body, would it require energy? > Rather it gives up energy Does it also give up force? > whether it's used to move something else or is given up as heat, breaking > things, whatever. I guess you could stop a truck without using any energy or breaking a sweat, then? > Several times over the course of the discussion I pointed out that the > infinite force--where the time over which it is applied and, by extention, [quoted text clipped - 7 lines] > is specify a point in the position/time curve where the curve is continuous > but at which the first and all subsequent derivatives does not exist. How does something change in zero time? A plain English answer will suffice. > Well, eventually, he finally got around to claiming that he actually meant > to include those other factors necessary to define the problem and we should > just try to forget that he spent considerable time trying to defend the > original proposition, as originally worded. It took me that long to figure out that you were being so pedantic. SignatureAKA "Dobbie The House Elf" > > >> By the way, I'm not just asking these questions > > >> because I'm too lazy to do any study, but that without any outside [quoted text clipped - 42 lines] > > If you were to stop the moving body, would it require energy? If there is a brick wall in front of the moving body, it stops it very nicely without expending energy. Instead, the wall gets energy from the truck. > > Rather it gives up energy > > Does it also give up force? Force and energy are two different things. There are forces present during the time when the momentum is changing. > > whether it's used to move something else or is given up as heat, breaking > > things, whatever. > > I guess you could stop a truck without using any energy or breaking a sweat, > then? Sure. There are passive systems for stopping runaway trucks that consist of barrels of sand. They don't require any energy to do their job. As with my brick wall example, they *get* energy from the truck. Of course as with the brick wall, the process is destructive, and I guess you might be inclined to argue that it takes energy to put the barriers back in place. That's true, but it's only an inefficiency in design. You could design a system that would not be destroyed in the process of absorbing the truck's energy. Stopping a truck requires having a method to get rid of energy, not a method of putting energy in. Friction just happens to be an easy way to get rid of energy, and we trade a one-time destructive design for cheapness and reliability. - Randy > There are passive systems for stopping runaway trucks > that consist of barrels of sand. They don't require any energy > to do their job. As with my brick wall example, they *get* > energy from the truck. Yeah, but motorcycles take longer to stop than trucks, the the "how to drive" manuals say so, RIGHT, muggle? On Feb 15, 4:12 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > There are passive systems for stopping runaway trucks > > that consist of barrels of sand. They don't require any energy [quoted text clipped - 3 lines] > Yeah, but motorcycles take longer to stop than trucks, the > the "how to drive" manuals say so, RIGHT, muggle? I don't recall discussing motorcycles, but the manuals I read said that trucks and buses have longer stopping distances than cars. Those manuals are written by government departments of transportation, who also collect the data. As usual, you have a counter position but no reference to support it, while every reference I found with data supported my claim. That's OK, we'll just add it to the ever growing list of confirmed real world things you don't believe in: - beamwidths from antennas - the inverse square law and free space loss - antenna gain - visual transduction in the retina - round trip travel times. Randy > On Feb 15, 4:12 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 8 lines] > I don't recall discussing motorcycles, but the manuals I read said > that trucks and buses have longer stopping distances than cars. Especially passive systems for stopping runaway buses and runaway motorcycles that consist of barrels of sand, RIGHT, muggle? That's in the manual I read, Newton's Principia. > Those manuals are written by government departments of transportation, > who also collect the data. Vote them out, politicians know even less physics than you. > As usual, you have a counter position but no reference to support > it, while every reference I found with data supported my claim. [quoted text clipped - 8 lines] > - visual transduction in the retina > - round trip travel times. - barrels of sand for stopping runaway motorcycles that take longer to stop than cars, the manuals written by government departments of transportation say so. baa... baa... baa... http://www.androcles01.pwp.blueyonder.co.uk/SR.GIF On Feb 16, 12:57 am, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > That's OK, we'll just add it to the ever growing list of confirmed > > real [quoted text clipped - 9 lines] > to stop than cars, the manuals written by government departments > of transportation say so. baa... baa... baa... OK sure, we'll add that - Fitch barriers (http://www.racesafety.com/ fitchbarr.html) Randy > On Feb 16, 12:57 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 15 lines] > - Fitch barriers (http://www.racesafety.com/ > fitchbarr.html) "For over 44 years, combat pilot, racer, safety engineer and inventor John Fitch has been involved with the myriad aspects of motorsports safety. Find out more about his contributions to safety, both on and off, the track." No, Yeah, so? On Feb 16, 5:06 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > On Feb 16, 12:57 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > > wrote: [quoted text clipped - 19 lines] > > No, Yeah, so? The line wrapped, but you couldn't figure that the "html" part might have been part of the URL. http://www.racesafety.com/fitchbarr.html > On Feb 16, 5:06 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 26 lines] > > http://www.racesafety.com/fitchbarr.html No, I'm not responsible for your sloppy posts. No, so you don't believe motorcycles take longer to stop than cars, even though government transportation department documentation backs me up, RIGHT, Blind Poe? No, you are a self-contradictory stooopid bastard, aren't you? On Feb 17, 1:16 am, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > On Feb 16, 5:06 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > > wrote: [quoted text clipped - 29 lines] > No, I'm not responsible for your sloppy posts. > No, so you don't believe motorcycles take longer to stop than cars, Read for comprehension. I said I don't recall reading any data on that question. So I don't know the answer. > even though government transportation department documentation > backs me up, Does it? If you have a cite, provide it. If the data supports a "yes" answer, then I'll probably believe "yes" is the answer. Why do you think data is more suspect when it is paid for by a government department of transportation? Who the hell else do you think does these experiments? - Randy > On Feb 17, 1:16 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 34 lines] > Read for comprehension. I said I don't recall reading any > data on that question. So I don't know the answer. No, that's OK, we'll just add it to the ever growing list of confirmed real world things you don't believe in. >> even though government transportation department documentation >> backs me up, > > Does it? If you have a cite, provide it. No, http://www.highwaycode.gov.uk/ > If the data supports > a "yes" answer, then I'll probably believe "yes" is the answer. No, you probably would, too. > Why do you think No, I don't really know why, it comes quite naturally. No, I think, therefore I am. > data is more suspect when it is paid for > by a government department of transportation? No, it is most suspect when it's a lie, no matter who pays for it. > Who the hell else do you think does these experiments? No, me. No, I have a lifetime's experience of driving and a knowledge of physics; it does not take longer for a bus to stop than a car no matter what government is in power. On Feb 17, 11:39 am, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > On Feb 17, 1:16 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > > wrote: [quoted text clipped - 44 lines] > > No, http://www.highwaycode.gov.uk/ You forgot we were talking about motorcyle stopping distance? OK, I'll try again. Do you have a "government transportation department" that compares motorcyle stopping distance to automobile stopping distance? If you can provide that, I can read it for you and tell you whether the motorcycle stopping distance is larger or smaller than the car's. - Randy > On Feb 17, 11:39 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 48 lines] > > You forgot we were talking about motorcyle stopping distance? http://www.highwaycode.gov.uk/ No, you forgot I gave a citation, fuckhead. No, I admit to having abandoned any hope of rational conversation with *you*. I'm trolling *you*, if you like. My responses to others are still with the intent of conveying substance and exchanging ideas. > http://www.highwaycode.gov.uk/ > > No, you forgot I gave a citation, fuckhead. This citation doesn't show squat. It's basically a front page for a search engine. I'm pointing it out to casual readers of this thread, since Androcles is a piece of sh.t. -Mike K. On Feb 17, 2:16 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> wrote: > > On Feb 17, 11:39 am, "Androcles" <Engin...@hogwarts.physics.co.uk> > >> >> even though government transportation department documentation > >> >> backs me up, [quoted text clipped - 8 lines] > > No, you forgot I gave a citation, fuckhead. That is not a cite about motorcycle stopping distances as there is no data about motorcyle stopping distances on that page. Is that slow enough for you? - Randy > On Feb 17, 2:16 pm, "Androcles" <Engin...@hogwarts.physics.co.uk> > wrote: [quoted text clipped - 14 lines] > > That is not No, did you snip something I missed? >> There are passive systems for stopping runaway trucks >> that consist of barrels of sand. They don't require any energy [quoted text clipped - 3 lines] > Yeah, but motorcycles take longer to stop than trucks, the > the "how to drive" manuals say so, RIGHT, muggle? The individuals "supporting" Mr. Dobson pretty much make my case for me. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > >> There are passive systems for stopping runaway trucks > >> that consist of barrels of sand. They don't require any energy [quoted text clipped - 5 lines] > > The individuals "supporting" Mr. Dobson pretty much make my case for me. The individuals supporting you are making a case for silence being golden. SignatureAKA "Dobbie The House Elf" > > >> There are passive systems for stopping runaway trucks > > >> that consist of barrels of sand. They don't require any energy [quoted text clipped - 7 lines] > > The individuals supporting you are making a case for silence being golden. As are the individuals supporting you. Since where silence is golden, speaking is dross. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays > > >> There are passive systems for stopping runaway trucks > > >> that consist of barrels of sand. They don't require any energy [quoted text clipped - 7 lines] > > The individuals supporting you are making a case for silence being golden. BTW, I want to thank you for bringing this up over here. The result has been a good 100 new visits to my webcomic. If things hold to form, that should be good for another dozen or so regular readers. SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@asmicro.com "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >> >> There are passive systems for stopping runaway trucks >> >> that consist of barrels of sand. They don't require any energy [quoted text clipped - 7 lines] > > The individuals supporting you are making a case for silence being golden. Just to give you the background to my statement, a student asked why buses take longer to stop than cars. Well, they don't. A bus has more rubber on the road than a car so the emergency stopping distance is roughly the same but a considerate bus driver is not going to slam the brakes on at every bus stop and see his standing passengers fall over. Keeping in mind this is a physics newsgroup, the muggle Poe accepted the premise and attempted to explain why buses take longer to stop than cars, and then cited government transportation documents in a flustered attempt to hide his goof. However, those same government transportation documents also state that a motorcycle takes longer to stop than a car -- which it may well do if it is on its side and sparks are flying from the footrests, as I found out the hard way when I was 18 years old and used my ribs to stove in a car's radiator. The car was not hurt, merely damaged. I was both hurt and damaged. Beware of muggles, they have no clue of real world physics. Notice the drooling moron you are communicating with steers well clear of math or physics, preferring to flame. He's a general phuckwit, we have many of them. >"Androcles" <Engineer@hogwarts.physics.co.uk> wrote in message news:7ypBh.285817$QY6.124648@fe1.news.blueyonder.co.uk... > "David L. Burkhead" <dburkhead@sff.net> wrote in message >> The individuals "supporting" Mr. Dobson pretty much make my case for me. >> [quoted text clipped - 8 lines] >a considerate bus driver is not going to slam the brakes on at >every bus stop and see his standing passengers fall over. That's interesting. I wouldn't have expected that. >Keeping in mind this is a physics newsgroup, the muggle Poe accepted >the premise and attempted to explain why buses take longer to stop [quoted text clipped - 5 lines] >when I was 18 years old and used my ribs to stove in a car's radiator. >The car was not hurt, merely damaged. I was both hurt and damaged. IC. >Beware of muggles, they have no clue of real world physics. >Notice the drooling moron you are communicating with steers >well clear of math or physics, preferring to flame. >He's a general phuckwit, we have many of them. Yes, it's interesting that the moment my slavering friend became informed that his arguments might be seen by his peers, he abruptly curtailed it. SignatureAKA "Dobbie The House Elf" >> "David L. Burkhead" <dburkhead@sff.net> wrote in message > [quoted text clipped - 35 lines] > informed that his arguments might be seen by his peers, he abruptly > curtailed it. Bullshit. For one thing, the only "support" you've got is someone who rejects and denigrates anyone who might actually be a "peer"--actual phycisists who know and respect actual physics. You've already demonstrated that you don't understand the math or the physics (things like limits, or the relationshp between work and energy), so there's not a lot of point in repeating the same old arguments which you didn't understand the first dozen times. Still, for amusement, let's run through a bit of math/physics. E = the integral from a to b of F dot dS where F is the Force vector and dS is the differential displacement vector. Now, for simplicities sake, let's take the case where F is constant, parallel to the direction of motion, and that there are no rotations--simple straightline movement using a constant acceleration. The more complicated cases lead to the same result but the math to get there is likewise more comlicated. That leads us to: E = F(b-a) or substituting distance d where d = b-a, we get E = Fd. A falling body, incidentally, so long as speeds are low enough that we can ignore air resistance (generally the case in the original situation) has a speed given by: v = sqrt(2*g*D) where g is the acceleration due to gravity and D is the distance fallen. For acceleration, a, the Force required is F = ma and the distance traveled going from v to 0 is given by d = v^2/(2a) or, substituting in for the velocity 2gD/2a or gD/a. Substituting these into the energy equation and you get: E = (ma) * gD/a. Simplify, and you have: E = mgD, which is simply the potential energy of the height. Notice that the magnitude of the force is no longer a part of the equation. Only the mass, the distance fallen, and the acceleration due to gravity contribute. In words, as the body falls, the potential energy of its height into kinetic energy and time never even entered into the equation except as units of measurement. When it stops, that kinetic energy has to be converted into other forms of energy--chiefly heat although some can go into things like elastic deformation (converted back into potential energy through a different mechanism). Did you understand it this time? SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>> "David L. Burkhead" <dburkhead@sff.net> wrote in message >> [quoted text clipped - 37 lines] > > Bullshit. Oh yeah, You make this claim and yet, here I am--and have been since it was brought to my attention that you sought support for your claims over here (and did so by misrepresenting my position). SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>> Yes, it's interesting that the moment my slavering friend became >>> informed that his arguments might be seen by his peers, he abruptly [quoted text clipped - 6 lines] > brought to my attention that you sought support for your claims over here > (and did so by misrepresenting my position). Show me where I did that. SignatureAKA "Dobbie The House Elf" >>>> Yes, it's interesting that the moment my slavering friend became >>>> informed that his arguments might be seen by his peers, he abruptly [quoted text clipped - 8 lines] > > Show me where I did that. Already been done repeatedly. A lot of it is tied up in a phrase you still don't understand "in the limit." SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>>>> Yes, it's interesting that the moment my slavering friend became >>>>> informed that his arguments might be seen by his peers, he abruptly [quoted text clipped - 12 lines] > still > don't understand "in the limit." A no-show, again, as usual. SignatureAKA "Dobbie The House Elf" >>>>>> Yes, it's interesting that the moment my slavering friend became >>>>>> informed that his arguments might be seen by his peers, he [quoted text clipped - 14 lines] > > A no-show, again, as usual. <shrug> If you didn't understand it the first dozen times, why should I assume you'll get it _now_? SignatureDavid L. Burkhead "Dum Vivimus Vivamus" mailto:dburkhead@sff.net "While we live, let us live." My webcomic Cold Servings http://www.coldservings.com -- Back from hiatus! Updates Wednesdays >>> Beware of m |
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