1
vote
1answer
65 views

Specific heat of aluminium as a function of temperature

I am trying to find the curve describing the specific heat of aluminum as a function of temperature between about 50K to 300K(or room temperature) for an experiment I am doing. Ultimately I need to ...
3
votes
0answers
23 views

Experimental results regarding non-extensivity in small systems

From a statistical mechanics point of view, the extensivity of thermodynamics arises from the fact that we can neglect interaction terms in the Hamiltonian. This allows us to infer that when we put ...
3
votes
1answer
238 views

Is cooling really exponential?

I did the following experiment: I took boiling water, put a thermomenter (from Vernier hooked up to a TInspire calculator) into it and pulled it out. Then we started measuring the temperature it read ...
2
votes
3answers
197 views

The cooling curve of tin during solidification

I'm going to measure the freezing point of tin by recording the cooling curve. It sounds like a dull experiment because all I have to do is to heat up the tin, wait for it to cool, and the computer ...
8
votes
4answers
377 views

Doesn't the use of a thermometer alter the temperature of the system?

If I place a mercury thermometer in hot water, heat energy will transfer from the water to the mercury inside the thermometer. Will this continue until thermal equilibrium is reached and thus the ...
2
votes
0answers
240 views

Theoretical or experimental violations of the 2nd Law of Thermodynamics? [closed]

Theoretical challenges to the 2nd Law? What are some the theoretical challenges to the 2nd Law? (cf. Čápek, Vladislav, and Daniel P. Sheehan. Challenges to the Second Law of Thermodynamics: Theory ...
4
votes
1answer
125 views

Is there valid physics behind the bodybugg?

The bodybugg is a faddish gadget whose marketers claim it can measure your body's daily energy expenditure. Their sales literature says: As reported in the British Journal of Sports Medicine, 2008 ...
1
vote
1answer
159 views

Isentropic vs Total pressure

I am confused between these two quantities: Isentropic pressure and Total pressure. Are they the same?
10
votes
3answers
735 views

Best way to chill a cup of coffee with cold water and 5 minutes [duplicate]

Initial data 1 x 3/4 full cup of hot coffee / tea / your favorite morning beverage cold water 5 minutes Considering that it's starting to get hot outside, and we all want to drink reasonably cold ...
1
vote
1answer
139 views

1/2 freeze a water bottle

Is it possible to quick freeze half of an unopened bottle of water or soda by putting half of the bottle in a subfreezing solution liquid nitrogen or other solution without freezing the whole bottle?
7
votes
1answer
400 views

Mechanical Equivalent of Heat

Recently I have been looking up James Joule's experiment regarding the mechanical equivalent of heat. After viewing some drawings of the apparatus, I assumed that the lines holding the weights would ...
6
votes
3answers
283 views

How can I determine the coefficient $k$ in $ \dfrac{dT}{dt} = -k(T - 100 \mathrm{^\circ C}) $?

I recently spend some time on cooking and I'm curious about the time evolution of the temperature of the water. I did some experiment and the temperature is of the form $$ T = 100 \mathrm{^\circ C} + ...
9
votes
3answers
667 views

How hot is the water in the pot?

Question: How hot is the water in the pot? More precisely speaking, how can I get a temperature of the water as a function of time a priori? Background & My attempt: Recently I started spend ...
0
votes
1answer
344 views

Best way to move teaspoon to dissolve sugar in a cup of tea

I know that there is asked questions about something like cooling down cope of coffee..etc, but this one is little different. My friend was watching TV program of English eating etiquette, and they ...
5
votes
3answers
302 views

experimental technique for measuring temperature of an ant

I am taking a course on thermodynamics. I have a question from my text(halliday & resnick,physics-1). They asked me to measure temperature of an ant or an insect or a small body,like a small ...
1
vote
2answers
468 views

How does blow-drying a mirror keep it from steaming up again?

After a hot shower, the mirror in my bathroom steams up. When I try to clear it with a towel, it immediately refogs. Yet once I use my hair-dryer, it will clear the fog and the mirror will stay clear. ...
1
vote
1answer
179 views

Calibrating an electronic temperature sensor based on power consumption

I'm working with an electronic temperature logger that is being affected by heat generated internally. How does one come up with a calibration equation to calculate a more accurate reading of ambient ...
3
votes
1answer
447 views

How to properly bake a ultra high vacuum chamber?

I need to get rid of water excess in my vacuum chamber, and for that there is the procedure of baking. In order to do that there are several things that one needs to consider, the power, heat load, ...
1
vote
5answers
203 views

Normal distribution of x, xdot

I have some real measurements from a process and I happened to look at the mutual distribution of (x(t), xdot(t)). I found that they seem to follow 2d normal distribution around (mu, 0). See image, ...
2
votes
2answers
2k views

Testing the temperature of an open flame

How, and what device do you need, to obtain the exact temperature of an open flame? For the purpose of this question, you wanted to maintain 375 degrees. You can control the flame, but have no idea ...
1
vote
1answer
181 views

Depalma Free Energy fields

Few years ago I read some papers about Free Energy, written by Bruce de Palma, a physicist who is said to be the inventor of the N-Machine, which is an device that works with free energy latent in the ...
4
votes
2answers
411 views

What are the easiest to get/make LN2 superconductors?

I am starting to build multistage Peltier cooler at the moment, and it should be able to reach -100C at least (but if I fail I can always get boring LN2). Doing some experiments with superconductors ...
9
votes
7answers
7k views

Explanation of “thermite vs ice” explosion

There are several videos of the reaction, where some amount of burning thermite explodes on a contact with ice. An "original" video: http://www.youtube.com/watch?v=IuPjlYxUWc8 A Mythbusters ...
324
votes
19answers
122k views

Cooling a cup of coffee with help of a spoon

During the breakfast with my colleagues, a question popped into my head: What is the fastest method to cool a cup of coffee, if your only available instrument is a spoon? A qualitative answer would ...
5
votes
2answers
537 views

Experiments that measure the time a gas takes to reach equilibrium

If you take two ideal gases at different temperatures, and allow them to share energy through heat, they'll eventually reach a thermodynamic equilibrium state that has higher entropy than the ...