i need a simple calculation of a stirling ltd surface area calculation per watt produced and would a very rough surface and very large surface area hinder heat flow if the distance to re generator is extreme /would folding the surface area of a flat plat ltr help increase the power of engine...
Referencing: http://www.vlsiinterviewquestions.org/2012/07/21/inverted-temperature-dependence/
Mobility decreases in a MOSFET with increasing temperature
However, referencing: https://www.quora.com/Why-does-resistivity-of-semiconductors-decrease-with-increase-in-temperature
Resistivity...
I am operating via finite differences.
Say for example, I have this pipe that contains a fluid. I have the boundary condition at x = x1:
k is the effective thermal conductivity of the fluid, T is the temperature of the fluid at any point x, hw is the wall heat transfer coefficient, and Tw is...
Just started this topic so I'm not sure if this is the correct way to solve this, any help would be appreciated.
mass of object x change in temp x specific heat capacity= heat
change in temp= heat/(mass of object x specific heat capacity)
Mass= 700kg
Specific heat capacity of steel= 0.42kJ/kgC...
I converted dm3 to m3, all the degrees to kelvins and found out the specific heat constants of iron and aluminium (0,45 and 0,91 KJ/kg K), but now i am failing to understand how this was supposed to be calculated. The equation given doesn't really help, as there are two unknowns in it: Q and the...
309 average temperature
$$\begin{array}{|c|c|c|c|c|c|c|}
\hline
t\,(minutes)&0&4&9&15&20\\
\hline
W(t)\,(degrees Farrenheit)&55.0&57.1&61.8&67.9&71.0\\
\hline
\end{array}$$
The temperature of water in a tub at time t is modeled by a strictly increasing, twice-differentiable function W. where...
Hi, I need to heat up a flat surface in a controlled way from room temperature to approximately 950 C. The surface will be some square meters large. Is there any way doing this without combustion, that is using a electric heating blanket? Does anyone know if such blankets exist? (Have already...
Hi, I've been given a homework to do based on 2D Ising model.
Ive already read plenty of articles bout 2d ising model but I'm not fairly certain about some things.
I got to do a chart similar to the one I attached. Correct me if I am wrong, but on the Y axis, I have to put average of...
I've got a kitchen bowl made of polypropylene, it states that the "heat resistance temperature is 90 degree cel", while on Google, I found that the melting point of PP is 160 degree cel.
I understand that melting point is the temperature in which the atoms/molecules change its state from solid...
I find that $$U=\int Z \epsilon D(\epsilon) e^{-\epsilon β}d\epsilon=\frac{gV}{(2\pi)^3}\int Z \frac{(\hbar)^2k^2}{2m}k^2 (4\pi)e^{-β\frac{(\hbar)^2k^2}{2m}}dk$$
where g=2s+1=2, $$Z=e^{βµ}$$ and $$D(\epsilon)=\frac{gV}{(2\pi)^3}k^2 4\pi$$ for the density of states
From here, I can use
$$c_v...
Hello,
I am interested in physics of cuprate high temperature superconductors (Cuprate_SC)
However, I heard that it is "out-of-dated" topic in solid state physics and almost impossible to find group/foundation to do research in this field.
I am doing PhD right now and I consider moving...
Suppose we have a body that isn't a black body, but has an arbitrary emission spectrum. In the general case, can the radiation from this body be characterized as having a temperature, and if so, how? If not, what conditions are needed to make the concept of temperature meaningful in this case?
Suppose we have two boxes of same material and same size but one have a hole in it and if we raise the temperature with equal amount then does two box expand equally?
What is temperature?
The simple definition I get in books is that it is the measure of coldness or hotness,but what in real it is at the atomic level what does happens to the atoms when we we work on substance by heating.
I'm releasing pressurized propellant into another chamber which is at atmospheric pressure, I want to estimate the temperature to which that chamber will drop to and the rate at which the liquid (collecting in the new chamber) will boil.
The second chamber is open to atmosphere via a small...
Any object with a temperature emits corresponding EM waves.
Thermal imaging works by considering our temperature of 37C/98.4F/310K, and it corresponds to 9.3um LWIR as per Wien's law.
I was thinking about the following summer scenarios in which how it would work.
1) If...
I want to know that why we have defined value of temperature of boiling point and melting point of water different on different scales, as I can think we need to know temperature so we have given a certain value to melting point and boiling point of water and we have given them some value but...
I tried modeling the problem quite a few ways. one was to say that the difference between the heat emitted by the room and the heat emitted by the bulbs would equal the heat absorbed by the room, and that could allow us to calculate temperature. This did not work. I'd appreciate your help
Question
(These are incorrect values)
Attempt
I used and then found the respective change in temperature.
However for the last question I have no idea, do I sum up the net change in temperature and use
But then what is the work and how do we figure it out?
I was taught that standard ΔS°, ΔG° and ΔH° are the corresponding quantities measured under standard conditions which I was told was 0.1M for solutions, 1 bar for gases, but importantly also at 298K.
On many places on the internet, however, I have read that 298K is not actually a standard...
imagine you burn something, like H2 in O2. let's say you have a nice flame with a temperature T. for the sake of this discussion let's assume that T is 1000.
what happens if you preheat both H2 and O2 to 1000 first? is the resulting flame temperature higher? does the flame look the same? what...
Problem:
We wish to find the temperature and the diffusion coefficient of water by measuring the velocity of pollen grains in the medium, due to brownian motion and other forces.
Attempt:
We have a video clip and are using the program Tracker to measure the position of the pollen grains over...
1) I do not quite understand how the phrase remain accurate to 1 second in 24 hours? , means ΔP = 1 second,
2) I also don't understand how pendulum period P should be 24 hours
What is the reasoning for both?
The solution is as such
P = 2π √(L/g) P' = 2π √((L+L α δT)/g)
ΔP = P'- P = 2π...
I'm not sure if this is the right place for this but I have a question about the relationship between current through a conductor and the heat dissipated by the material.
Given the current, resistance, and specific heat of a material as well as the specific spatial dimensions is there a way to...
A uniformly accelerating observer registers a temperature
T = 1/2π
Or an observer hovering near a black hole. According to current understanding, what are the best ideas about the origin of this temperature?
Basic Procedure
The experiment basically involves finding the null point on the Carey Foster's bridge with the PRT as the unknown resistance and using a Resistance box as the variable resistance.
In the above diagram, P and Q are 2 fixed resistors of equal resistances.
For obtaining the first...
Hi guys, I'm new here.
I have been analyzing the behavior of cast iron melts in induction furnaces and realized that at the end of the melt the current increases slightly. The power remains the same. Physically, does anyone know the reason?
I imagine to be related to the magnetic permeability...
So, my apparatus consists of a basic wooden plank with a nail on one end and a guitar tuner on the other. I plan on using a heating lamp to control the temperature of the apparatus, which is placed inside an insulation box, and use a non-contact infrared thermometer to measure the temperature of...
How can I calculate the temperature changes of a pressurized gas as it is in a cylinder, then as it is when flowing into another vessel?
my best guess was using the ideal gas law (with help from this forum), but I feel like I'm using it wrong.
P = 300bar or 296.08 atm
V = 112 L (is this...
Hi!
I have a question:
Is it possible to calculate incandescent light color temperature based on it''s input voltage? For example, if for example 100w light bulb rated for 220V gives light with color temperature of 2800k then what would color temperature be at 110v? As voltage is now 2 times...
I am studying the rotary compressor and I have understood that the stagnation pressure and stagnation temperature both increase in the rotor stage (as energy is being added). I also read that in the stator stage the stagnation temperature remains a constant but there is loss of stagnation...
What is the most precise way to log temperature in the laboratory? I am concerned with resolution and precision here, not accuracy.
RTDs don't seem to cut it. Almost all that I have looked at and tried only have a resolution of around 0.1 deg C. I was hoping for 10X better than that-
Thanks...
Summary: The transition Sn(s, gray) ⇌ Sn(s, white) is in equilibrium at 18°C and 1 atm pressure. If ΔS = 8.811K mol for the transition at 18°C and if the densities are 5.75 g/cm3 for gray tin and 7.28 g/cm3 for white tin, calculate the transition temperature under 100 atm pressure
The...
*Here, no mention of these reservoirs being a gas, so I'm not sure if I can use the PV=nRT or the P*V^(gamma)=K equation.
SO I am left with only the 1st law.
If I can write dQ1( going out from object 1)= Cp (indep of T)*(Tf-T1)
dQ2(coming into the object 2)= Cp*(T2-Tf)...
Is there such a thing as a partial temperature of a gas in a mixture? Partial pressure is commonly accounted for and used. It seems that if there are molecules of different masses colliding in a mixture, their average respective velocities in a mixture should be different based on transfer of...
Good Morning,
I am not coming up with an answer in my search, could anyone confirm or deny whether a circuit conductor would experience more temperature rise with three-phase current than if the same R.M.S. current was single-phase. Alternating Current, 60 Hertz.
If you want to know why I want...
I set up an experiment where I put a fixed quantity of water in a cylinder fitted with a movable piston. I slowly add heat to the system, as expected both the temperature and the volume will increase but the volume will not increase significantly (steep line), until some point where some gas...
Hi, so I found this on another old "AP" High School Finals Exam.
I think I may be super lost.
Because the only way that I can think about is KE = 3/2kT. And then that the difference of the Kinetic Energy of the air Particles is the Q supplied by the heater inside the air dryer.
So ## \frac...
Hello all!
Basically I intend to create an environment inside a chamber with variations of CO2 percentages, using electrovalves.
The mixing gas is always compressed air + CO2.
For example: create a 50% CO2 concentration with a total pressure of 2 Bar.
The chamber is closed, and compressed air...
Summary: Hi, I'm doing an assessment for Physics on Optics topics, but I can't really explain how the CV affect the RV
CV : Focal length of convex lens
RV : Temperature of water after 20 minutes under the sun
How I should explain for the temperature difference? 🤔
Please help, Thanks.
Hello, I would like to ask you something about prevention from temperature equalization.
I would really appreciate it if you can answer.
To begin with, I want to store specific material into a breathable microfiber bag and place it inside a safe.
This material is susceptible to heat and...
I delved a bit into the kinetic theory of gases and it got me wondered how it is discovered that the temperature, and thus heat capacity, is dependent on the number of degrees of freedom of a molecule or atom.
I know that from the piston experiment a certain constant value can be found for the...
I have a compressed pure gas at a specific temperature and volume. (T1, V1) It suddenly (adiabatically) expands until it's at ambient pressure and a specific temperature. (P2, T2). Given: T1, V1, T2, and P2, I want to find P1 and V2.
There's a great example in wikipedia which is almost...
Dear Experts,
I have read from various sources that the temperature of a gas is related to the "average translational kinetic energy" of a molecule of gas. When there are molecules that support motion other than translational ,which may also have rotational and vibrational motion, How does those...
So, quick disclaimer: i am very young. only 12. i might also misspell some thing or not translate it correctly. i just like physics, so don't expect much.
So, i was reading in my science textbook (as a hobby) and it asked to describe some examples, in which i should find out wether the work on...