Temperature Definition and 1000 Threads

This article in Science mag news is about a fabric that can, let more heat (via IR) out in hot weather, or flipped over, keep more heat in the cold Here is the Science article (not free). The fabric also let's gasses and humidity pass through because it has nano-pores. It has 4 layers: 2...

Hi guys, I am currently working on my master thesis. I am supposed to make a dynamic model for a gas system and have some trouble setting up the energy balance. I am a noob when it comes to uploading pictures, so I don't have a figure for this, but let's consider a general control volume (CV)...

Homework Statement A certain mass of water in a copper pot is heated over a stove that releases joules of heat to heat the water. Later the same mass of water in an aluminum pot is heated over another stove that releases the same amount of heat in order to heat the water. Then the water in...

Hello! First post here so go easy on me. I am a Physics enthusiast, but I fear I am a layperson when it comes to the field. Most of what I know comes from low level college classes and the youtube channel PBS Spacetime. I have a question that might be a ridiculous one. But here goes. (Go easy...

1. The problem statement, all variables, and given/known data I'm having a little trouble understanding planetary subsolar temperatures. The first equation comes from viewing the absorbing and radiating areas of an object as the same and the second equation comes from viewing the absorbing area...

a microchannel of length 2L and width h in the thermal cycling region. the temperature profile ...(1) the cyclic temperature profile leads to a time dependent density ...(2) using the mass conservation equation i.e. ...(3) and momentum balance equation i.e. ...(4) we have to find the exact...

Hello, After the last post I completely changed the system. I now have a new system. Based on the feedback from last time I increased the time in contact with the block significantly. And I have made it a two stage unit. Here are the parameters for the first stage. An Aluminum block. (assume...

Are there any type of minerals/molecules/elements even solids that when dissolved, in say a glass of room temp water, can raise or lower the temperature? Examples...

The only way for me to move 1200 degree steel is with a magnet. The magnet loses its magnetism at 800 degrees, though, causing some pieces to fall and potentially injure people. Is there a way to electrically boost the magnetism of an existing magnet, apply an additional field to the magnet...

During a thermodynamic process, the state variables of an ideal gas, measured in kPa, m3, and oC, varied in the following way: P2 = 2P1 V2 = 3V1 T2 = 8T1 What is the temperature increase of the gas, T2 −T1 ? I've been given an answer of 4780 and I'm not sure how to get there?

Homework Statement since specific heat c changes with temperature, but its treated as a constant in the heat formula, so that means that heat formula Q=mc(T2-T1) is just an approximation? correct? I see some texts define heat as Heat, q, is thermal energy transferred from a hotter system to a...

since specific heat c changes with temperature, but its treated as a constant in the heat formula, so that means that heat formula Q=mc(T2-T1) is just an approximation? correct? I see some texts define heat as Heat, q, is thermal energy transferred from a hotter system to a cooler system that...

Homework Statement Question: https://imgur.com/a/8rUw1 Graph: https://imgur.com/a/Z1oBO Homework Equations Answer for Q1 (Just the formula) : https://imgur.com/a/uesqN The Attempt at a Solution I have realized that from 1-2, there is an increase in pressure, decrease in volume and increase...

Hello all; I am new in this forum, currently in High School. For some time now, I have been looking online for a relationship between temperature and magnetic flux density of a ferromagnet; below the Curie point. However, I can't seem to find any relationship or formula. Do any of you know...

Hello all, I am not sure my question will totally make sense for those of you who now this topic well but as I am new to it I hope I can be forgiven. My problem is to work out how much water will condensate as a stream of moist air is expanded through a turbine. So far I was using Antoine's...

Homework Statement I need to find the time it takes to heat a vessel of water which is closed. Here is what I have: Specific heat capacity of water: 4184 J kg^-1 K^-1 Density of water: 1000 kg m^-3 Volume of water added and volume of vessel: 500 L or 0.5 m^3 Heat capacity of the vessel: 91000...

I'm trying to understand why $$\left(\frac{\partial P}{\partial T}\right)_V = -\left(\frac{\partial P}{\partial V}\right)_T \left(\frac{\partial V}{\partial T}\right)_P$$ where does the minus sign come from?

I thought of another question(s) :) does temperature affect the rate of the decay at all? Does temperature effect the energy of the decay; in that the energy of the electron anti neutrino would be higher?

<mod: moved from intro> Hello all! This is my first post in this forum. I am struggling with the following question regarding a hair dryer. The hairdryer can be seen as a cilinder with a fan inside blowing air at speeds from the table below and 1 nichrome wire which heats up consuming different...

Hello, I have a question regarding bath pasteurising cider in bottles. The bottles are carbonated with CO2 and capped, I heat the water up to a temperature of 70deg.C I use a test bottle filled with water and with a cork in the top, I use this to monitor the temperature inside the bottle. So my...

Homework Statement (a) A block of copper at a pressure of 1 atm and a temperature of 5 degree celcuis is kept at constant volume. If the temperature is raised to 10 degree celcius what will be the final pressure? (b) If the vessel holding the block of copper has a negligibly small thermal...

Hi everybody, I seem to be having trouble coding a function that returns the integer value at which degrees celsius is equivalent to degrees fahrenheit. Here is the question: Write a function that will find a temperature that is the same in both Fahrenheit and Celsius. First define two...

Problem Description: I have a solar panel of some surface area, material, and thickness mounted to an enclosure. The panel is isolated from the enclosure at some distance with a multitude of materials (air, insulation, plastic, metal) between the back surface of the panel and interior volume...

Question: The multiplicity of an ideal gas is given by g(U) = A.U3N/2, where U is the energy of the gas, A is a constant and N is the number of particles in the gas. Prove that the energy of the gas given a temperature T is U = (3/2).N.kb.T Attempts: My first thought was to...

Hello, I wanted to know, if someone knows of a realistic option of, how to cut barrium ferrite magnets without using a rock saw and without demagnetizing the magnet obviously? Thanks in advance everyone.

I had no idea where to place this, so my apologies if I chose the wrong topic. Hi, For a certain application I need to heat very small (< 0.2 mm^3) quantities of ethanol until it vaporizes (78 °C) and then cool it down again until it's a liquid again. The hard part is that this all needs to...

Homework Statement The molar energy of a monatomic gas that obeys van der Waals' equation is given by E=\frac{3}{2}RT - \frac{a}{V} where V is the molar volume at temperature T and a is a constant. Initially, one mole of such a gas is at temperature T_1 and occupies a volume V_1. The gas is...

Well, I have to show mathematically that T remains unchanged in phase change. I know it comes from sperimental evidences, but my professor asked to show it with "numbers". So I thought to go like this: (dH_l)/dt ≈ (dm)/dt) h_v + Q Energy balance for system (let's say it is liquid and changes...

Can we consider temperature in general as "property" without even been associated to well defined states of matter. Like the boiling and melting points.

For my research I am trying to study the temperature change of a warm fluid (air) flowing over a cold surface, but I have not studied fluid mechanics. Does anyone know of an equation that can be used to analyze this problem? To give some reference, the hot air is 49 Celsius and the cold air is...

Homework Statement A mixture of hydrogen, carbon monoxide and carbon dioxide is being fed to a compressor at 2.0 bar and 25 C. The overall flow rate is 17.47 SCMS and its composition is 73.5 mol% H2, 13.7 mol% CO and the balance CO2 The compressor operates adiabatically and reversibly with a...

HI, I have application where i need to lift metal plate, 3kg weight, ( 3mmX 15mm), 250degree.C hot, for the period of 1min and put it back. For lifting purpose i am using actuators. As i have no opportunity to make hole in plate i have to use magnet for lifting purpose. I got Electromagnet...

why does the water become more acidic as temperature goes up. H2O <-> (H^+) + (OH^-) . why does this dissociate into the ions more at higher temperatures. also even if it does dissociate more it should not become more acidic as for every H^+ formed a OH^- is formed.

Hello, I was giving a random thought to Ohm's Laws and thermal dilation. As a general rule we are told that ohmic resistors will increase their resistivity if their temperature increases. Does this take into account the fact that its dimensions will change due to thermal dilation? This would...

Homework Statement Im doing a MC simulation with the ising model 2D. How can i calculate the Binder cumulant g as a function of temperature. To calculate the Binder cumulant, i will perform a scaling analysis f (finite scale scaling). Homework Equations U_L = 1 – { M^(4)_L / [ 3.(M^(2)_L)^2 ]...

Homework Statement Homework Equations ## V=IR## The Attempt at a Solution This is an I-V graph so the slope must represent ##\frac{1}{R} ## Now, $$ R∝Temperature$$ {This is assuming that the wires are of metal} Now , since the graph is of ##\frac{1}{R} ## , the steeper the slope the higher...

Hey guys, recently I have conducted an experiment investigating the effect of temperature (K) against magnetism (mT). I have found two formulas and understand that they are for both linear and non linear relationships but why does the function change from linear?

Hello, This is for my independent game development project. I am aiming to simulate simple environmental properties in grid-based world. I have world made of cells (or blocks) and I consider each physical property to be constant and uniform in given cell. Some properties spread from a cell to...

Hi everyone, I have recently done an experiment testing the effect of temperature on magnetism through measurement of magnetic flux at a constant distance away from the measuring device. I used a range of 0-90 C for neodymium and bar magnets, and found a reasonably linear trend, with a similar...

Homework Statement Two containers hold an ideal gas at the same temperature and pressure. Both containers hold the same type of gas but container B has twice the volume of container A. The internal energy of the gas in container B is (a) twice that for container A (b) the same as that for...

I know that in a para magnetic material the magnetization increase on cooling. What will be the same effect on a diamagnetic material,considering the fact that Curies law doesn't hold good on diamagnetic materials.

Homework Statement Consider the slab shown in Fig. 18-18. Suppose that L 25.0 cm, A 90.0 cm2, and the material is copper. If TH 125 C, TC 10.0 C, and a steady state is reached, find the conduction rate through the slab. Homework Equations Pcond = Kc *A*(TH - TC)/L K = 401 W/m*k The Attempt at...

Homework Statement A 0.530 kg sample of liquid water and a sample of ice are placed in a thermally insulated container. The container also contains a device that transfers energy as heat from the liquid water to the ice at a constant rate P, until thermal equilibrium is reached. The...

I can't understand why a gas passing through a porous plug experiences change in its pressure and why does the cooling or heating process depends upon the initial temperature

I was not sure where to post this question so if anyone has a better home for it please advise. I am trying calculate how much temperature a given mass is required to be heated to (oven setting) to reach a target temperature on the surface of a metal like copper. I also need to know this...

This seems simple, but I have some confusion. I'm trying to refine a numerical simulation to get away from my isothermal assumption, to account instead for isentropic temperature and pressure changes in pressure tank with an orifice. Given an insulating air tank of volume ##V##, containing air...

I am currently performing a school experiment in which I am testing when citric acid decays. We are juicing lemons, filtering them to get a higher concentration of citric acid, placing them in water baths from 10 to 90 degrees Celsius and then titrating them against one mole of sodium hydroxide...

Hello I have got a question and i don't know the answer. Please help me. I have a n doped semiconductor. How does the number of conduction electrons depends on temperature and compare the situation to an intrinsic semiconductor? Do i look at the intrinsic density, because when it is n doped...

Hello, Nice easy question for you all today: I would like to know how the speed of sound in steel varies with temperature. A google search didnt reveal a great deal, so if a physicist could confirm the relationship, that would be much appreciated. I know that: v = √shear modulus/density...

If I have a closed cylinder with a fixed air volume inside and a piston on the open end I need to calculate how much the piston will move as the temperature changes through a range of 100 degrees F? Air volume vs temperature?