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June 23 Information
I'm looking for useful physical formulas of the form:
Where the are physical properties of the same type (e.g. of energy, or of electric charge, and likewise).
Those physical properties don't have to be denoted by the same letter in the formula.
They should be denoted by not more than three letters, excluding indices if needed.
The indices: "total", "initial", "additional", mentioned above, don't have to be mentioned in the formula, either. They should be understood, though, from the standard meaning of the letters/indices mentioned in the formula. Therefore, formulas of the type should be ignored, because none of those Es (=energies) is usually interpreted as "initial".
What about integrations, eg the amount of electric charge on an object = integration over time of the current flowing through a surface that encloses the object.? (+ initial charge)
Graeme Bartlett (
talk)
11:21, 23 June 2024 (UTC)reply
Your example uses too many letters. I must use three only (the Xs), and all of them should be of the same type, as indicated above.
HOTmag (
talk)
16:03, 23 June 2024 (UTC)reply
"Where the are physical properties of the same type" - they have to be for the equation to make sense. see
Dimensional Analysis. i can't off hand think of a non trivial equation that is simple enough for your requirements. weight_today=weight_yesterday+change_in_weight_per_day?
Greglocock (
talk)
22:16, 23 June 2024 (UTC)reply
They have to be [of the same type], for the equation to make sense: Yes, of course. I'd only wanted to exclude hypothetical examples meaning eg: "What I like to talk about = energy + electric charge". Admittedly, it's only a hypothetical example, because it does not reflect any useful formula, whereas what I need should be a useful formula, as indicated in the title. This requirement also excludes your last suggestion.
HOTmag (
talk)
06:59, 24 June 2024 (UTC)reply
Thank you. To me, the time formulas are better than the Post Newtonian expansions, because I need precise equations rather than approximations.
HOTmag (
talk)
18:20, 24 June 2024 (UTC)reply
Does it have to be symbolic, or does this count: "When the voltage is increased by 100 volts, the new voltage will be 150 V + 100 V = 250 V"[1]? --
Lambiam06:52, 24 June 2024 (UTC)reply
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a
transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the
current reference desk pages.
June 23 Information
I'm looking for useful physical formulas of the form:
Where the are physical properties of the same type (e.g. of energy, or of electric charge, and likewise).
Those physical properties don't have to be denoted by the same letter in the formula.
They should be denoted by not more than three letters, excluding indices if needed.
The indices: "total", "initial", "additional", mentioned above, don't have to be mentioned in the formula, either. They should be understood, though, from the standard meaning of the letters/indices mentioned in the formula. Therefore, formulas of the type should be ignored, because none of those Es (=energies) is usually interpreted as "initial".
What about integrations, eg the amount of electric charge on an object = integration over time of the current flowing through a surface that encloses the object.? (+ initial charge)
Graeme Bartlett (
talk)
11:21, 23 June 2024 (UTC)reply
Your example uses too many letters. I must use three only (the Xs), and all of them should be of the same type, as indicated above.
HOTmag (
talk)
16:03, 23 June 2024 (UTC)reply
"Where the are physical properties of the same type" - they have to be for the equation to make sense. see
Dimensional Analysis. i can't off hand think of a non trivial equation that is simple enough for your requirements. weight_today=weight_yesterday+change_in_weight_per_day?
Greglocock (
talk)
22:16, 23 June 2024 (UTC)reply
They have to be [of the same type], for the equation to make sense: Yes, of course. I'd only wanted to exclude hypothetical examples meaning eg: "What I like to talk about = energy + electric charge". Admittedly, it's only a hypothetical example, because it does not reflect any useful formula, whereas what I need should be a useful formula, as indicated in the title. This requirement also excludes your last suggestion.
HOTmag (
talk)
06:59, 24 June 2024 (UTC)reply
Thank you. To me, the time formulas are better than the Post Newtonian expansions, because I need precise equations rather than approximations.
HOTmag (
talk)
18:20, 24 June 2024 (UTC)reply
Does it have to be symbolic, or does this count: "When the voltage is increased by 100 volts, the new voltage will be 150 V + 100 V = 250 V"[1]? --
Lambiam06:52, 24 June 2024 (UTC)reply