17th-May-2008, 07:59 PM
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Moderator
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Join Date: Dec 2007
Posts: 897
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Quote:
Originally Posted by LMagic007
That above description is somewhat misleading. Instantaneous speed is not simply the rate at which you travel. Instantaneous speed is the speed or rate of travel at a given moment or instant in time.
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A pretty fair description of instantaneous speed. 
Quote:
Originally Posted by LMagic007
The rate at which you travel is simply distance over time.
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Quite so.
Quote:
Originally Posted by LMagic007
Getting back to the main point though, if energy cannot be instantaneous, then nor can power, because power without time is meaningless. Power requires time to have meaning.
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It doesn't.
Instantaneous implies in an instant with no intervening time, making time zero and if time is zero then work cant be done and if work cant be done then power does not exist.
Quote:
Originally Posted by LMagic007
Power is a rate at which work is performed or the amount of energy expended over a unit of time. This rate is a ratio, in which two measurements ( 1. unit of energy - joule and 2. time ) are related to each other to derive meaning. If no time passes then this rate cannot exist, yet to be instantaneous requires no passing of time, meaning time is zero, therefore power cannot exist if time is zero. Power W requires 1 joule over 1 second. If time does not pass then power does not exist and thus cannot be derived. If no work is done then power does not exist. For work to be done time must pass. i.e. for 1 unit of work being 1 joule, 1 second must pass. However, to be instantaneous requires no passing of time. We thus have a null contradiction.
However for descriptive purposes in terms of measuring energy over a very short space of time a different interpretation of instantaneous is sometimes given. i.e. without perceptible time. This might explain one reason why in fact the term instantaneous energy is used in areas of science and technology.
It's clearly not pragmatic to have zero time, meaning without passing of time, or no intervening time, because this would mean zero energy, zero work done and zero power. Thus pragmatically speaking, instantaneous time is applied to simply mean, a very short space of time and usually sub-second but greater than zero time. i.e. for pragmatic purposes no perceptible time, being a very short space of time.
Regardless of all this though, it does not change the fact that the intended meaning of the articles is clear.
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Last edited by LMagic007; 2nd-June-2008 at 06:57 AM.
Reason: 007 remarks were used but not in qoted form. corrected with quote
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