Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

[Phys-L] A RESEARCH PROJECT (AND A GOOD LAB)



A GOOD LAB FOR ALL AND A RESEARCH PROJECT FOR SOME

1) THE INVITATION BELOW (in lower case text) WAS POSTED IN AUGUST WHEN
MANY OF YOU WERE PROBABLY AWAY. ONLY TWO PEOPLE MADE COMMITMENTS TO
PERFORM THE SUGGESTED EXPERIMENT (ONE WITH TWO STUDENTS AND ONE WITHOUT
STUDENTS). IT IS NOT TOO LATE TO MAKE A COMMITMENT.

2) THE FRENCH PAPER THAT PROMPTED ME CAN BE DOWNLOADED AT
<http://lenr-canr.org/acrobat/FauvarqueJabnormalex.pdf>

3) I DID NOT REALIZE THIS IN AUGUST BUT IT IS NOW OBVIOUS THAT THE
FRENCH SETUP IS SUITABLE FOR A STUDENT LAB IN PHYSICS OR CHEMISTRY. NO
SPECIAL ELECTRODES OR HIGH VOLTAGE POWER SUPPLY IS NEEDED -- ONLY
ORDINARY WATER AND AN IMMERSION HEATER. BY USING THE SETUP OF FIGURE 1
(WITH AN OHMIC HEATER ONLY) STDENTS WILL COLLECT DATA TO TRACE THE PINK
CURVE (SEE FIGURE 2). THEN THEY WILL TURN THE ELECTRIC CURRENT OFF AND
COLLECT THE TEMPERATURE-VERSUS-TIME DATA. FROM THAT CURVE THEY WILL
DETERMINE THE AMOUNT OF THERMAL ENERGY LOST IN 5 MINUTES DUE TO
CONDUCTION, CONVECTION AND RADIATION. ASSUMING HEAT LOSSES BY THESE
THREE MECHANISMS NEAR 95 C ARE NOT VERY DIFFERENT FROM THOSE AT 100 C,
AND KNOWING THE HEAT LOSES BY ALL FOUR MECHANISMS, STUDENTS WILL BE
ABLE TO SHOW THAT L IS INDEED CLOSE TO 2260 J PER GRAM.

HERE IS A NUMERICAL ILLUSTRATION BASED OF FIGURE 2: (P=400 W TIME=5
MIN, ENERGY=400*5*60=120,000J). THE AMOUNT OF WATER EVAPORATED IS 36
GRAMS. BUT THE ENERGY USED TO EVAPORATE THAT AMOUNT IS LESS THAN
120,000 J BECAUSE ONLY PART OF ELECTRIC ENERGY WAS USED ON EVAPORATION.
SUPPOSE WE KNOW THAT 40,000 J IS LOST IN 5 MINUTES VIA THREE OTHER
MECHANISMS. THEN

L = (120,000-40,000)/36 = 2222 J PER GRAM

4) THIS MIGHT ALSO BE A GOOD PROJECT FOR THE ANNUAL AAPT APPARATUS
COMPETITION.
LUDWIK

Dear colleagues:
Please read what has just been posted at my website as:

http://blake.montclair.edu/~kowalskil/cf/252clauzon.html

It is an invitation to participate in a collective student-oriented
project. The idea of turning what I wanted to do into a collective
Internet project was prompted by the ongoing debate about scientific
methodologies. Give your students a chance to participate in a research
project they can easily understand.
P.S.
Comments on this list (in addition to private messages would be
appreciated).
_______________________________________________
Phys-L mailing list
Phys-L@electron.physics.buffalo.edu
https://www.physics.buffalo.edu/mailman/listinfo/phys-l