Basic units output in mathcad
Basic units output in mathcad
(OP)
Hey all, I'm an undergrad using mathcad for the first time to do some basic calcs for a design class.
I'm having an issue with units being assigned in the program. (File is attached, work begins on page 3).
I've assigned a value for "P" in lbf and a value for "a" in ft. When these two values are multiplied, the output is in [ft^2*lb]/s^2.
Later on in the calculations, I have a length, "L", but the program has assigned that to be gallons, not "feet" as I would like it.
How can I use the program to control these units?
Thank you!
I'm having an issue with units being assigned in the program. (File is attached, work begins on page 3).
I've assigned a value for "P" in lbf and a value for "a" in ft. When these two values are multiplied, the output is in [ft^2*lb]/s^2.
Later on in the calculations, I have a length, "L", but the program has assigned that to be gallons, not "feet" as I would like it.
How can I use the program to control these units?
Thank you!





RE: Basic units output in mathcad
RE: Basic units output in mathcad
You should always check to see if the symbol you are using is already taken. The first time you type L=, it would have converted to L:= had L not been previously defined. L= should result in L=1*L because its a built-in unit
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RE: Basic units output in mathcad
RE: Basic units output in mathcad
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RE: Basic units output in mathcad
RE: Basic units output in mathcad
The "L" for liter makes practical sense even if it doesn't make pure SI sense. The symbol "l" looks too much like the symbol "1" (in fact in old typewriters the same striker came up with either one or ell). Had MathCad followed the SI convention the confusion would have legion.
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Basic units output in mathcad
The bigger issue, of course, is that every year or so, someone new to Mathcad will do something similar to the OP and wonder why the units aren't working. I wonder if this is why Mathcad isn't used as much as it could be, since the units handling is a major selling point for me.
TTFN

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RE: Basic units output in mathcad
David Simpson, PE
MuleShoe Engineering
In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
RE: Basic units output in mathcad
TTFN

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Need help writing a question or understanding a reply? forum1529: Translation Assistance for Engineers
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RE: Basic units output in mathcad
The (optional) use of the upper-case "L" for litre (or "liter" if you're American - but that's a different topic!) has in fact been a part of the SI standard definition since 1979, precisely because of the typography issue.
The litre, and the symbol lower-case l, were adopted by the CIPM in 1879 (PV, 1879, 41). The alternative symbol, capital L, was adopted by the 16th CGPM (1979, Resolution 6; CR, 101 and Metrologia, 1980, 16, 56-57) in order to avoid the risk of confusion between the letter l (el) and the numeral 1 (one).
Ref: Note (f) to Table 6 "Non-SI units accepted for use with the International System of Units" in "The International System of Units (SI)", 8th edition 2006, Bureau International des Poids et Mesures
http://www.bipm.org/utils/common/pdf/si_brochure_8...
See also:
http://en.wikipedia.org/wiki/Litre#Symbol
http://physics.nist.gov/cuu/Units/outside.html
http://julianh72.blogspot.com