Newsgroup: it.cultura.linguistica.inglese
Titolo: Come leggere formule matematiche

Ciao a tutti,
ho qualche difficoltà a leggere in inglese coretto formule matematiche. 
Ad esempio, come leggo le seguenti formule:
30 Km/h
40 m^2 (metri quadri..)
35%
V=R*I (R moltiplicato I..)
2 = radice quadrata(4)
Spazio=V/t  
Qualcuno mi sa indicare qualche sito utile sull'argomento?
Grazie dell'attenzione.
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 Spazio=V/t
Space equals V divided by t.
-- 
Tchau, -João do Sabão

 Spazio=V/t
?
Does this have something to do with RC or L/R time constants?
Joe from Massachusetts


We usually, by convention, write certain elements in formulas in the same
order.
RC not CR, RL not LR, IE not EI, IR not RI, I²R not RI², IZ not ZI, etc.
Joe from Massachusetts

 wrote in message
news:0ITsl.33375$Tp5....@newsfe13.iad...

To clarify, the letters R and L would never appear as "RL" in an electronics
formula, nor would the letters R and C appear as "RC" in an electronics
formula, because of the phase differentials involved.  RL and RC are used as
descriptors only. An RL circuit is one that contains resistive and inductive
components, and an RC circuit is one that contains resistive and capacitive
components.
Joe from Massachusetts

 Does this have something to do with RC or L/R time constants?
I expect that it was
   s = v t
where s = distance.
Antonio

 that contains resistive and capacitive components.
RC crops up: the time period for a 555 timer, ferinstance.
Antonio

 Joe from Massachusetts
Sorry,my mistake.. I mean V=S/t or Speed = distance/time


 Grazie dell'attenzione.
Aggiungo ancora alcune cosette. 
Come si leggono i seguenti numeri?
5E-5 (ovvero 5 per 10^-5)
-0.002
e^-t (numero di Nepero elevato -t)
Grazie a tutti per l'aiuto!


 e^-t (numero di Nepero elevato -t)
e to the minus t

 5E-5 (ovvero 5 per 10^-5)
There is a difference between Scientific Notation and Engineering notation.
In Scientific Notation, simple powers of 10 are used, thus .00005="5 times
ten to the minus five" in Scientific Notation..
Engineering Notation is a modified version of Scientific Notation which
deals only with powers of ten which are mutiples of three. 5E-5 is only the
description of a number which may appear in a computer program, but when
actually written out by an engineer would be "50 times ten to the minus
six".  If you are making calculations on a calcucator, and the result is "5
times 10 to the minus 5", and you hit the key which converts from Scientific
Notation to Engineering Notation, the display will change to "50 times 10 to
the minus 6".
Joe from Massachusetts

 wrote in message
news:Dzzvl.151443$fM1.1...@newsfe14.iad...

The original example, 5E-5, is not correct. It should be 50E-6.
Joe from Massachusetts

 wrote in message
news:WtCvl.122041$EO2....@newsfe04.iad...

What I meant is not that 5E-5 is an error, but is simply not an example of
Engineering Notation, since -5 is not a multiple of 3.
When engineers do calculations, such as those in resistance, inductance, or
capacitance, they are only concerned with the powers of 10 which are
multiples of 3.
10E0     1×10^1    10.000 000 000 000  10 Farads (F)
10E-3    1×10^-2     0.010 000 000 000  10 milliFarads (mF)
10E-6    1×10^-5     0.000 010 000 000  10 microFarads (uF)
10E-9    1×10^-8     0.000 000 010 000  10 nanoFarads (nF)
10E-12  1×10^-11   0.000 000 000 010  10 picoFarads (pF)
In this example, 10E-5 would be meaningless, but we might be led to believe
that the writer intended for it to mean 10×10^-5, which is equivalent to
0.000 100, which is equivalent to 100E-6, or 100 mF. Or maybe he meant
something else?
Joe from Massachusetts

 0.000 100, which is equivalent to 100E-6, or 100 mF. Or maybe he meant
100uF
Joe from Massachusetts

 multiples of 3.
But I don't think e.g. mathematicians or physicists follow this
convention.
I certainly never have, though I am aware of it.