Temperature Definition and 1000 Threads

I'm putting together an idea about a weapon (insert hand-wavy science here) that fires extremely high temperatures a very short range (100 feet or so). A Heat Shotgun, if you will. The idea is that this weapon, with a single blast, could turn the majority of a human sized creature to literal...

Hello, A question I can't seem to find a simple answer to is, what happens to the Fermi-Dirac distribution at T grows large? Mathematics suggests that it approaches 1/2, like it does when the energy becomes equal to the Fermi energy. Or, are we not allowed to use the F-D distribution for high...

Homework Statement At low temperatures, the specific heats of metals is described by the expression ## c=kT + AT^3 ## , where k and A are constants. Here the first term describes the contribution of free electrons and the second the lattice contribution. How much heat is required to raise the...

Are the temperature over 24 hours normally distributed? Over 1 year? Over 15 years? Is there a difference in distribution depending on the time span Are MIN temperatures per day i.e. the coldest temperature measured over a 24hr period normally distributed? Over one month Over one year Over 15...

So say I have a PV-Thermal array and assuming standard test conditions. How would I calculate the temperature of the water coming out of the system? The thermal output of the system is 67.5kWp with a maximum flow rate of 65L/h. Approximately 500m of 3/4" pipes.

I'm doing some work on solar and I'm reading about properties of lamination materials, particularly EVA lamination. Anyway, one of it's properties is 'temperature stability' but I can't find a clear definition of what this means. EVA lamination is sandwiched in between a solar cell, so I can...

Since the temperature of a gas is related to its average molecular energy and the pressure to the average molecular momentum, it would seem that a Lorentz transformation would somehow relate the two. Does anyone know of related work?

can power supplies cause temperature fluctuations in a circuit? Or, instead, are they sensitive to temperature fluctuations in the environment, which can cause temperature fluctuations in a circuit?

Guys... If there is a bar, half of it is Copper and another half is Steel (Length wise) and both of its ends are at 1000K and I want to know how to find the temperature- length curve. this was an interview Question by the way.

Hello experts... I have an experiment pool boiling. The test section filled with DI water, and use thin flat copper as the heater that connected to the power supply. I want to ask how to measure or calculate the heater temperature if I only have the resistance, voltage and current data reading...

Consider the internal energy of a gas and solid (different materials) both at the same temperature, which material has the larger potential energy and why? Do they also both have the same kinetic energy? Finally is the definition of temperature as the average kinetic energy of the particles only...

on earth, we have the poles being very cold and mostly frozen, while the equator is very warm and humid. i would like to know specifically what causes this. i know it is partially because of their exposure to the sun, but i'd like to know some of the details and factors involved. i'd also like...

What happens to current in a solar cell when temperature increases? I found two sources with different information. 1) As solar panel temperature increases, its output current increases exponentially while the voltage output is reduced linearly.' 2) Whereas, this second website says short...

Hello, I am currently working on a project which involves compressing air at high pressures and temperatures. I spent hours having a look for a pressure and temperature dependent equation for the dynamic viscosity of air but the only ones I could find were all temperature dependent only, such...

1. Homework Statement Homework Equations KE = 3/2 R/NA T The Attempt at a Solution By using the formula above, I used 2.4 x 10^-14 J as the mean translational KE , but it should be 1.2x10^-14 , why? I thought the mixture contains both deuterium nucleus and the proton? Why half KE of mixture?

The index of refraction for a gas depends on temperature, as well as pressure. What is an experiment that would determine the temperature dependence of the index of refraction of air?

Homework Statement 5 g of water at 30°C and 5 g of ice at -20°C are mixed together in a calorimeter Find the final temperature of the mixture. Water equivalent of the calorimeter is negligible,specific heat of ice=0.5 cal/g°C and latent heat of ice =80 cal/g. Homework Equations...

Can the temperature of an object be derived from the EM Waves it emits? I know that everything having a temperature over absolute zero emits thermal radiations. The hotter the object gets, the higher the frequency of the wave goes. But for example if I have a hammer which emits a wave xHz...

After a cookout on Saturday, I left two cans of Coca-Cola in my bag. Around Monday morning which is almost two days later, when I left for school, the cans were still cold with moisture on it. The next day, I put another can of Coca-Cola in the car and only left it overnight to see what the...

Greetings, I get that increased temperature increases pressure. But does increased pressure increase temperature. For example: 1) If I press down on a table with a heavy object, does it increase its temperature. 2) Or does the pressure of the crust and the mantle of the Earth, contribute...

I am taking a protein supplement that has far too much sodium in it. If I took the amount I need every day, I would far surpass the safe upper limit of daily sodium intake. I had the idea of dissolving the pea protein powder in water, filtering out the sodium, and then evaporating the water...

I've been trying to wrap my head around the relationship between temperature increase of an object at a distance and temperature of a heat source. From what I've found, the temperature increase of an object from thermal radiation is affected by the inverse square law...

Hello all, I am working on a few test scripts to test the life of a hydraulic cylinder. (It is a mechanically operated cylinder and has a positive displacement) The testing will involve thousands of continuous pump and retraction operations, due to which the temperature of the piston seal and...

Homework Statement This isn't a specific problem, but my professor told us that we can calculate the size of a star if we know the temperature of it. Homework Equations Stefan-Boltzmann Law, Wien's displacement law. The Attempt at a Solution With the temperature i can also get the intensity...

Is there a formula or equation to find out how heated a place x meters/kilometers from a heat source will be, if we have the size of the heat source, it's shape, it's surface temperature, it's inner temperature, everything? + the distance between source of heat and the specific location is...

What determines the surface temperature inside a pot of boiling water, right over the heat source? Can it go much over boiling temp if the water's just gently boiling?

Homework Statement Homework Equations R2=R1(1+alpha(t2-t1)) The Attempt at a Solution R1=250/5=50ohms R2=250/3.91=63.94ohms R2=R1(1+alpha15degrees(t2-t1)) 63.94=50(1+1/254.5(t2-15)) t2= Now I found this online but the answers provided still don't match, 84.25 being the closest. When...

From what I know, temperature is defined to be the average kinetic energy of molecules within a system while heat is said to be the total kinetic energy of molecules. I know this might be something we can never achieve in real life but here's how my thought process went. Imagine you have a box...

The thermal efficiency of a reversible heat engine is solely a function of the temperature of the two reservoirs. η = f(θH,θC) = 1 - (QC/QH) (QC/QH) = 1 - f(θH,θC) (QC/QH) = Ψ(θH,θC) The simplest function that can be used is T1/T2 (QC/QH) = T1/T2 In order to define the Kelvin scale we assign a...

Homework Statement https://drive.google.com/file/d/0BxPEJS0qVOpeWENSREI1RlNsNDQ/view?usp=sharing A hub is connected to a shaft with a shrink fit (pressurized oil assembly, grease removed). The material of the hub is quenched and tempered steel (ReH = 450 N/mm2) and the material of the shaft...

I was reading this thread on Reddit about estimating drag using only a temperature profile. I was reading the responses, and I feel like most of them are missing something. Since this forum is more science-focused, what do you guys think...

Hi! These days I've been studying thermodynamics of quantum systems, and in so a very basic doubt come to me... I hope you guys can help me: When we study the usual hamiltonians of quantum mechanics (H-atom, harmonic oscillator, etc.)... Are these hamiltonians modeling the system at...

One is always told that a heat pump (heating water) should receive return water with a temperature as low as possible. I've never really understood why. My initial thought is that if the return is higher, then it's "easier" for the heat pump to heat the water up to whatever supply temperature...

Homework Statement A steel rod and an aluminum rod of equal length and diameter are placed end to end and secured so that they cannot flex. The rods are heated to the same final temperature, and the steel is found to increase in length by one-tenth of a percent. If the total length of the rods...

Hi, I'd like to know how I'd put together, either elegantly or at least in physical terms, that surely water evaporation in a large pool of V volume and S surface is influenced by wind (increased by it as opposed to having side barriers), temperature (increased by direct sunlight as opposed to...

Homework Statement Suppose you walk into a sauna that has an ambient temperature of 57.0°C. Calculate the rate of heat transfer to you by radiation given your skin temperature is 37.0°C, the emissivity of skin is 0.95, and the surface area of your body is 1.60 m2. I solved this first part and...

I was playing around with numbers and found that the equivalent temperature for Hawking radiation from a Planck mass black hole is ~5×1030 K. Later, I saw that the Hagedorn temperature for strings (where the partition function is expected to diverge) is reported to be around ~1030 K. I thought...

Starting a car: the voltage drops from 12V to 7.2 V, it is 0 degrees out, and 150 amps are pulled from the car. What is the temperature coefficient of the resistor? I have NO idea how to do this. Help please!

Homework Statement a)a stationary railroad whistle is sounded. An echo is heard 4.0 seconds later by a train's engineer. If the speed of sound is 343 m/s, how far away is the reflecting surface? b) If the temperature of the air increased, how would this change your answer? Homework Equations...

Good day to all, Hi, i would like to ask if there is a way to calculate the temperature change at a given time. I will use this as a basis for my study which is about designing an ice container and i would like to know how long does my ice last given its own temperature and the outside...

Homework Statement Suppose we drop a lead ball of mass M into water of mass m from a height h and allow everything to settle down. What is the temperature change of the water? Assume that the container is well insulated. Homework Equations Potential Energy = mgh dU = mcdT where dU is the...

Ok, so I could do an experiment on this first, but I decided to see if anyone knew beforehand. So basically my question is will different properties of the same temperature, exposed to the same temperature, cool/heat at the same rate? For example would a more viscous liquid cool as fast as...

Considering how hot brake rotors get under hard street and race track braking, what is the typical heat range experienced buy the actual wheel in contact with the rotor and hub?

Homework Statement An 8 cm3 ice cube (temperature = 0.00 °C) is dropped into a glass with 3 dL juice which results in the ice cube being melted. By doing this, the juice drops to a temperature of 3.00 °C. What was the temperature of the juice before the ice cube was added? (Treat juice as water...

I have a combustion process, and have calculated the net enthalpy of my inlets and outlets. Some of the energy released by the combustion is used to heat a cooling stream, maintained at temperature 46degC. I wish to calculate the power required to maintain this cooling stream temperature: I was...

At room temperature, particle energy is 0.025eV. Neutron capture reaction has big cross section when neutron is in room temperature. Theoretically, so does an electron. At 0.025eV, the electron velocity should be only 93.78km/s. Unfortunately almost no way to cool down an free electron to so...

Homework Statement 1 kg of moist air and 1 g condenses. What will the change in the temperature of the moist air be? Heat of Vaporization = 2.5*10^6 J/kg 2. The attempt at a solution The moist air will warm due to condensation. Heat of Vaporization=2.5*10^3 J/g Specific heat at...

Hi everyone, I am looking for basic elements resistivity vs. temperature laboratory measurements charts. Anyone has ideas where to look for? Regards

Mod note: moved from non-HW forum section Apparently doing math homework on Physics Forums helps me think more clearly. The d-part of this question gave me a headache, and I already wrote all of this LaTeX code on the homework side of this site, so I figured I'd post it even though I solved it...

Homework Statement I did an experiment involving the speed of sound at different temperatures. I placed two microphones at a fixed distance apart and I measured the time taken for a sound wave to travel between the two mics. I repeated this for different temperatures. I want to make a graph for...