Calchemy - Units Calculator V1.0
(iPhone Application)
Calchemy
is an exciting new tool which allows you to perform
dimensional arithmetic, analysis, and
conversions using any standard units.
Calchemy
"understands" the relationships between these units
and performs conversions for you automatically as
needed. It also checks your equations to ensure
that they are always dimensionally correct.
Please note: Calchemy™ was previously sold for Windows under the name Unicalc™.
The
following examples provide a brief introduction to
some of Calchemy's features.
Basic Features
To
calculate the required horsepower for a motor which
could raise a 2000 lbf elevator to the top of a 10
story building (assuming 12 feet per story) in 1
minute, you could enter the equation:
2000
lbf * (10 * 12 feet) / 1 minute ? horsepower
Indicating that you want to multiply 2000 pounds
force by 10 times 12 feet, divide that by 1 minute,
and then express the final result in horsepower.
Calchemy
would respond:
=
7.2727273 horsepower
If, on
the other hand, you had made a mistake in the
original equation and left out the "/ 1 minute":
2000
lbf * (10 * 12 feet) ? horsepower
Calchemy
would have responded with a Dimensional Mismatch
dialog containing:
TIME^-1
Indicating that the left hand side of the equation
was missing a factor of 1/TIME -- the equation was
not dimensionally correct, and therefore, could not
be evaluated.
Calchemy
can also be used as a simple dimensionless
calculator by eliminating the "?" and result unit
from the equation. For example, you could enter the
equation:
2+3*5
Calchemy
would respond with the algebraically correct answer:
= 17
More Advanced
Features
You could
also enter the original equation in the following
less explicit form:
2000
lb; 10 stories; 12 feet/story; 1 minute ? horsepower
Indicating that you want to combine 2000
pounds, 10 stories, 12 feet/story, and 1 minute in
such a way that the equation is dimensionally
correct, and then express the final result in
horsepower.
Calchemy
would again respond:
=
7.2727273 horsepower
This
example illustrates the following features:
Solving
By Dimensional Analysis
The ";"
operator tells Calchemy to use dimensional analysis
to determine whether its operands should be in the
numerator or the denominator of the equation. In
this example, Calchemy placed the first three
operands in the numerator and the last operand in
the denominator. This allows you to be less
involved with the actual mechanics of the equations.
Overloaded
Units
The "lb" unit is an
overloaded unit, meaning that it has more than
one common definition. It is primarily defined as "lbm"
(pounds mass) and secondarily defined as "lbf"
(pounds force).
Calchemy
automatically uses the appropriate definition, again
based on dimensional analysis. In this example,
Calchemy used "lbf". This allows you to naturally
use units with multiple common definitions.
Free
Units
The
"stories" and "story" units are called free units.
Free units are units which are not actually
understood by Calchemy, except in that they are new
and unique dimensions which must "cancel out" in the
end. This allows you to enter equations in a more
natural format.
Pluralized
Units
The
"stories" and "story" units also illustrate that
Calchemy understands basic pluralization rules
for units. This, again, allows you to enter
equations in a more natural format.
We hope you enjoy Calchemy.
| Image 1:
Calchemy displaying results of previous
calculations as a new calculation is being
entered, selecting a unit of time for the
result.
|
Image 2:
Calchemy displaying the new calculation with
the selected unit of time (hr) used for the
result.
|
| Image 3:
Calchemy displaying the details of the unit
of time (hr) selected for the result.
|
Image 4: Calchemy about to send its results to the e-mail application.
|
