Re: HP48GX/49G/+/50G woking with lists

In article <lctl05ltd6e3vs9j9pm6n2bo0g94cgnh1l@xxxxxxx>,
Harold A. Climer <Harold-Climer@xxxxxxx> wrote:

This week the students in my Electricity and Magnetism Lab
did an experiment to study how resistance of a Metal changes with
temperature. We used a light bulb(Tungsten filament) Power Supply, a
Voltage and Current sensor and plotted a graph of voltage vs. current.
Using the Raw data a resistance was calculated using Ohm's law. From
the resistance they were able to calculate a Temperature using the
following equation:
Rt= Ro(1+a(T-To))
Rt: Resistance at Temperature T
Ro: Resistance at room Temperature approx. 20 Degrees C
a: Tungsten Temperature coefficient 4.5 E -3 K^-1
To :Room Temperature 20 Degrees C

Question: is it possible to put the Voltage and Current data in two
lists an multiply the lists together to get a list of resistances?
If that is possible, is it possible to apply the above equation and
solve for a list of temperatures. By this I mean apply the equation to
the list of resistances and get a list of temperatures back.
I have done all this by hand to check their work. I calculated the
resistance and used the solver to find T.
I do not know why I didn't think about list calculations before.
Harold A. Climer
Dept Of Physics Geology & Astronomy
U.T. Chattanooga
Room 406A Engineering,Math & Computer Sicence Building
615 McCallie Ave.
Chattanooga TN 37403
Harold-Climer@xxxxxxx

If you have two lists of numbers of equal size (number of elements in
list) on the stack at levels 1 and 2 then the * operation will give a
list of equal size of their term by term products.

E.g., {2. 3. 2.} { 4. 5. 6.} * gives {8. 20. 12.}

Note that you can solve your equation for T
giving T = (Rt/Ro -1)/a + To
so consider a program like
\<< 1
\<< Ro / 1 - a / To + \>>
DOLIST
\>>

where your values for Ro, a, and To are stored under those names.

When applied to your list of resistances, Rt, this program will produce
a list of T's

So that altogether with a voltage list and a current list on the stack
and values of Ro, a, and To stored under these names the whole program
would be

\<< * 1
\<< Ro / 1 - a / To + \>>
DOLIST
\>>

An alternate program with the same result is

\<< 2
\<< * Ro / 1 - a / To + \>>
DOLIST
\>>

Hope this helps.
.

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