Temperature Definition and 1000 Threads

Suppose a wire made from an unknown alloy and having a temperature of 20.0°C carries a current of 0.529 A. At 52.4°C the current is 0.378 A for the same potential difference. Find the temperature coefficient of resistivity of the alloy. tempinital = 20C tempfinal = 52.4C currentInital = .529A...

Homework Statement Carnot engine A has an efficiency of 0.60, and Carnot engine B has an efficiency of 0.80. Both engines utilize the same hot reservoir, which has a temperature of 650 K and delivers 1200 J of heat to each engine. Find the magnitude of the work produced by each engine and the...

I am trying to compute the density of argon given the following conditions: T = 7000 K P = 21331 Pa For typical gases, I do not believe the ideal gas law would hold for such a high temp&low pressure regime, but since Argon is largely non-reactive, do you guys think using the ideal gas law would...

I'm taking an engineering heat transfer course as an elective. 1. Homework Statement Copper tubing is joined to a solar collector plate of thickness t, and the working fluid maintains the temperature of the plate above the tubes at To. There is a uniform net radiation heat flux q”rad to the...

Hey everyone, I found this video on Youtube of this guy boiling water by reducing the pressure: I'm not sure how the gauge he's looking at works but I think this is the vacuum instrument he's using: https://us.vwr.com/store/catalog/product.jsp?product_id=4789427 ^It says that it provides...

Homework Statement A container contains a given mass of ice and a given mass of water both at 0 degrees Celsius. A given mass of aluminum is heated up to some temperature and submerged in the water-ice mixture. No heat enters or leaves the container. Given the specific heat of water and...

Hi. Dunno if this makes much sense. If radiation is emitted from a star with a certain frequency, does that frequency change, if that radiation travels through areas of different temperatures?

Hello If I take an extreme case, where a body has only an internal potential energy with zero internal kinetic energy, does this body have a temperature? Another question related to it: if two objects A and B having different temperature: A: having only internal potential energy and B having...

I'm aware of the concept of rubber as an entropic spring and how increasing the temperature increases the modulus/stiffness of the rubber. I've seen the experiment of how heating a strip of rubber supporting a load will cause it to shorten. But also a rubber will transition from its glass-like...

Do sound waves increase the temperature of the medium they are traveling through?

Homework Statement A Ti Rod is to be put into a furnace to try and increase the carbon content of the rod. Initially, the carbon content of the rod is 0.2%wt. The carbon content of the furnace is 1.0%wt. What would the temperature have to be in order to get a final carbon content in the Ti rod...

Homework Statement I[/B] have some difficulties proving that the ideal gas temperature is directly proportional to absolute temperature defined by the second law of thermodynamics. Homework Equations The ideal gas temp. is defined by the ideal gas equation: pV=NkTi(T), where k is Boltzmann's...

Homework Statement [/B] Homework Equations $$W=P\Delta V$$ $$\Delta U=nC_v\Delta T$$ The Attempt at a Solution . [/B] The gas is slowly heated. The temperature increases and the pressure increases as well. But since volume increases, the increases in pressure is nullified. The process is...

domainwhale submitted a new PF Insights post High Temperature Low Temperature Duality for the Ising Model on an Infinite Regular Tree Continue reading the Original PF Insights Post.

Hello everyone! I recently read some information about the equipartition theorem and degrees of freedom in thermodinamics. I read that for the linear N-atomic and non-linear N-atomic molecules in order to allow the vibrational degrees of freedom to appear we need a really high temperature. I...

Would it be possible that you could create a black hole from heating something really hot. I heard Vsauce said if you heat something hot enough that it's wave length of the light released is smaller than the plank length, it would become a black hole. That means that the energy would be on the...

In my chemical thermodynamics class/notes (and other references I've used) it is stated throughout that internal energy U is a function of entropy and volume , i.e. it's "natural" variables are S and V: U = U(S,V) I suspect that I must take this "axiomatically" and move on. Since U is a state...

Donor ionization energies are calculated via the hydrogen-like model and use the static dielectric constant and effective mass to modify the screening between the electron and the donor. Nice and simple, I get it. But in a material the ionized electron needs to go someplace - presumably the...

For my bachelor project, I am in need of an air tight (or very, very near air tight) container, which can withstand 750 C. My original thought was to have a steel container with a lid and gasket, but I was unable to find any gaskets that got anywhere near that. Does anyone know of a gasket...

Homework Statement The problem is in the context of convection in the troposphere Show that when an ideal gas expands adiabatically, the temperature and pressure are related by the differential equation \frac{dT}{dP} = \frac{2}{f+2} \frac{T}{P} Homework Equations Ideal gas law PV = nRT...

In the past, reciprocating engine platforms have prevented the use of thermal insulating materials like ceramics due to, among other reasons, abrasion and vibration. One of the problems in the past has been the movement of the piston and piston rings over the cylinder wall where the insulating...

Hey guys, I have been wondering about this for a long time, and I can't seem to reach a solid conclusion. If temperature of an object is related to the movement of its atoms, then is it true to say that a moving object have a higher temperature?

Consider a sealed can of liquid refrigerant-134a in a room at 25 •C .Now if the lid is opened slowly and some refrigerant is allowed to escape, the pressure and temperature in the can start dropping rapidly.A thermometer inserted in the can will register -26°C when pressure drop to 1 atm. ,which...

Homework Statement Homework Equations $$PV^{\gamma}=\mathrm{constant}$$ The Attempt at a Solution Initially, the piston will get a velocity ##v##. But the chamber will move too because of the forces exerted by the gas. Since total external force is zero, velocity of centre of mass is...

I am trying to find the temperature of a star given its wavelength in micrometres, but I am not sure if my conversion is right therefore don't know if the answer is correct. Star A has a maximum emission wavelength of 1 μm and Radius 100 Rsun. What is its Effective Temperature and Luminosity...

Homework Statement Imagine a wet thermometer whose bulb is covered with a wet wick at 1 atm. Temperature of the water happens to drop during the process of evaporation. Homework Equations N/A The Attempt at a Solution Does evaporation lower the temperature of water just by removing...

Could turbine exhaust temperature be negative Celcius? My calculations yield 176 K. Is that possible? Inlet conditions are 7.8 MPa and 625 K. Exit pressure is 1 atm. (100 kPa.)

Hello everybody I am an architecture student working on a facade system and because I do not have much physics knowledge I stumbled across a question I can't answer myself: If my facade is actually a thin parallelipiped glass tank filled with water, how do I measure the temperature changes of...

Hi folks, This is a question about how to calculate entropy change when there is a temperature change involved. I got the correct answer to this, but I don't actually understand why it's correct..! Any help is much appreciated. Homework Statement One mole of liquid bromine is heated from 30...

I am interested to use a pyrometer to measure the temperature of a graphite heater while it is being heated (upto 1200 degC). The heater is located inside a small chamber filled with liquid cyclohexane . For viewing purpose of the pyrometer the chamber is having a viewport of Quartz. The...

http://arxiv.org/ftp/cs/papers/0701/0701016.pdf The above is link of Kafri's paper I was just studying at high school when I found this theoretical scientific discovery proposed by an enough notable Israeli physicist Oded Kafri. He made a unique unification or link between second law of...

On the epoch of last scattering, the universe became transparent and the typical CMB photon was "free" to travel the universe. The corresponding radiation was of a black body temperature of ~3000K. My question is: after the last scattering, the universe was still hot and, I presume, emitting...

I know that peltier plates are for cooling(mostly :smile:) but I wish to try out heating other substances using peltier plates. I'm planning to use 3 peltier plates (TEC1-12712) [maximum temperature difference of 70 degrees measured at 25 degrees / Maximum temperature difference of 80 degrees...

I have learned that temperature is defined as the vibration of particles. However, in vacuum, there is no particles. In reality, no absolute vacuum can be done, so I can't find answer online. Do you think the temperature (in Kelvin) is zero or undefined? Thank you.

I just went out to my car to retrieve my laptop. My car is at about 1 degree C, my house is at about 20 degrees C. I soon noticed condensation forming on the screen and it occurred to me that condensation was probably forming inside as well on the electrical components. The combination of...

Does temperature depend on the kinetic energy, or internal energy ?? Does it only depend on the movement of the molecules, or also the potential energy of molecules??

Homework Statement A liquid is enclosed in a metal cylinder that is provided with a piston of the same metal. The system is originally at a pressure of 1.00 atm (1.013 x 105 Pa) and at a temperature of 30 °C. The piston is forced down until the pressure on the liquid is increased by 50.0 atm...

Homework Statement My questions are based on a graph. I am trying to figure out the standard ΔH change for the graphed reaction and the standard entropy change. (1) What is the standard enthalpy change for the graphed reaction? (A) -31 KJ/mol (B) 0 (C) +12 KJ/mol (D) +11 KJ/mol (2) What is...

is there a way to calculate the themperture of something like a fire, if you know the thermal energy it produces.

The HadCRUT4 global surface temperature anomalies in tabular form include confidence intervals. The GISS surface temperature data is available in tabular text form here http://data.giss.nasa.gov/gistemp/tabledata_v3/GLB.Ts+dSST.txt - but it doesn't include any confidence intervals. Can...

I plan on using a 1 ft long, 0.005" diameter platinum wire as part of an electrode. The wire will be bare but will be inside a hollow plastic tube that has an inner diameter of 0.08". It needs to be able to carry a maximum of 1 mA for a length of 10 minutes, while not exceeding 60oC. I'm not...

The measurement of electrical resistance as a function of the superconductor's temperature yields fundamental insights into its properties. The Critical Temperature, Critical Current Density, and the Critical Magnetic Field, can all be obtained through variations of a basic experiment. I would...

Homework Statement Na has a bcc structure with molecular mass of 22.99 gr/mol, mass density of 0.971 gr/cm^3. The average speed of sound in Na (at room temperature=300K) is 3200 m/s. Calculate the Debye temperature for Na Homework Equations I worked out this equation to calculate the Debye...

Homework Statement Two moles of an ideal gas undergo a reversible isothermal expansion from 3.37×10−2m3 to 4.29×10−2m3 at a temperature of 29.6 ∘C. What is the change in entropy ΔS of the gas? Homework Equations pV=nRT The Attempt at a Solution W=∫V2V1pdV, I don't know how to use this...

Hello there, this is a fact that I can't understand thinking about it... Energy has to be given so that the inter molecular bonds can be broken, and energy goes in when there are formed (even though that sounds very counter intuitive to me), but why is the energy all distributed to potential...

I wonder why we can find temperature (or pressure )when the other property value is given.Lets say we have a rigid tank, which contains 50Kg of water at 90 degree celsius. If we look up the thermodynamics table, we can find the saturation pressure 70.14 kpa and definite liquid and gas specific...

Hi All, I'm working on an automated chiller control system for final year project. It is a logic control that automatically set the chill water supply temperature based on current demand load and the chillers performance curve to achieve the best efficiency COP for the system. For a variable...

Hello, I'm reposting this 'cause I think it's more relevant here than where it was posted before. Not sure how to delete the other one... I'm trying to plot the heat capacity as a function of the temperature from some small temperature to Debye's using numerical summation over the energy (shown...

Hi all, so when you heat something up the molecules begin to move faster. This is seen when you steam a tea kettle. So my question is when its very cold outside and there is no wind, it is much more comfortable then when there is cold wind whipping about your body. If molecules moving faster are...

Hello. The measurement of electrical resistance as a function of the superconductor's temperature yields fundamental insights into its properties. The Critical Temperature, Critical Current Density, and the Critical Magnetic Field, can all be obtained through variations of a basic experiment. I...