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Physics/heat transfer anommaly


QUESTION: We have set up an assessment based on the assumption that insulating aluminium cans with fleece will slow down the heat loss (described below). We are consistently getting results contrary to the intuition. The uninsulated can hold the temperature nearly as well as the one warped with 3 layers of fleece and  better than cans wrapped up in one or two layers of fleece. Fleece is dry.  Would appreciate help with interpreting those result as i am at loss to explain it to students.

Steps 2, 3 and 4 need to be done QUICKLY so that you get good results.
1.   Set up the cans as shown. Place the three cans with fleece around them into the cup holders provided.

ANSWER: I get one step.  That makes it kinda impossible to answer the question.

---------- FOLLOW-UP ----------

QUESTION: Sorry, here is a full method. Essentially the temperature drops the quickest in can with one layer of fleece, and slowest in naked can and can with 3 layers of fleece
1.   Fill the jug with hot water from the urn and carry it back to your table. Carefully and QUICKLY fill each can with hot water to the brim (top).
2.   QUICKLY Insert a thermometer into each can, put a layer of fleece over the top and use the peg to hold the thermometer in place (as shown below).
3.   QUICKLY Take the initial temperature reading for each of the cans and record it in the table below. Start the timer
4.   Measure the water temperature in each can every TWO minutes for 30 minutes and record in the table provided.

OK, still a little short.  There is no "as shown below" image attached to your question.  So far, from your written description it doesn't make any sense.  I'd recommend that you change the order in which you pout into the cans and see if the result is repeatable, and perhaps take some numbers.  It might also help if I knew the heat capacity and mass of the fleece.


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Dr. Stephen O. Nelson


I can answer most basic physics questions, physics questions about science fiction and everyday observations of physics, etc. I'm also usually good for science fair advice (I'm the regional science fair director). I do not answer homework problems. I will occasionally point out where a homework solution went wrong, though. I'm usually good at explaining odd observations that seem counterintuitive, energy science, nuclear physics, nuclear astrophysics, and alternative theories of physics are my specialties.


I was a physics professor at the University of Texas of the Permian Basin, research in nuclear technology and nuclear astrophysics. My travelling science show saw over 20,000 students of all ages. I taught physics, nuclear chemistry, radiation safety, vacuum technology, and answer tons of questions as I tour schools encouraging students to consider careers in science. I moved on to a non-academic job with more research just recently.

Ph. D. from Duke University in physics, research in nuclear astrophysics reactions, gamma-ray astronomy technology, and advanced nuclear reactors.

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