Thermal energy Definition and 206 Threads

The term 'thermal energy' is used differently, and often loosely, in different contexts. It refers to several distinct physical concepts, such as the internal energy, or as the enthalpy, of a body of matter and radiation; or as heat, defined as a type of energy transfer (as is thermodynamic work); or as the characteristic energy of a degree of freedom,




k


B



T


{\displaystyle k_{\mathrm {B} }T}
, in a system that is described in terms of its microscopic particulate constituents, where



T


{\displaystyle T}
denotes temperature and




k


B





{\displaystyle k_{\mathrm {B} }}
denotes the Boltzmann constant.

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  1. P

    What happens to the temperature of an object in vacuum?

    Hi guys. I was wondering, what happens to the temperature of a object if it's put into vacuum? Say you have a box of steal (something that transfers thermal energy fast between the inside and outside). Inside the box you have a rock. The rock is held in the center of the box using...
  2. C

    Problem Relating Temperature and Thermal Energy

    Homework Statement An ideal gas is at 40°C. The gas is cooled, reducing the thermal energy by 35%. What is the new temperature in °C?Homework Equations I'm not sure there is one? The Attempt at a Solution Since, in an ideal gas, thermal energy is proportional to temperature, I multiplied 40°C...
  3. B

    Thermal Energy problem - Ice placed in water

    Homework Statement An ice cube at its freezing point is placed in nested Styrofoam cups which contain 240g of water at 21.5 degrees C. If the final equilibrium temperature when the last trace of ice melts is 15 degrees C, what was the mass of the ice cube? Homework Equations mCΔt = -mCΔt...
  4. T

    Calculating thermal energy released when aluminum cools an solidifies

    Homework Statement While forming a 1.5kg aluminum statue, a metal smith heats the aluminum to 2700 degrees C, pours it into a mould, and then cools it to a room temperature of 23.0 degrees C. Calculate the thermal energy released by the aluminum during the process. Homework Equations Q =...
  5. M

    Gas heated under constant pressure - thermal energy transferred?

    Homework Statement A 1.0 sample of nitrogen gas (diatomic)is heated at constant pressure from 300K to 420K, Cp (nitrogen) = 29.1 Jmol-1°C-1 The thermal energy transferred to the gas is? 1. 8370 J 2. 12,200 J 3. 34.90 J 4. 3590 J 5. 12.20 J Homework Equations KE = 1/2mv2 =...
  6. N

    Transforming kinetic energy into thermal energy

    Homework Statement Two cars collide head on while each is traveling at 80 km/h. Suppose all their kinetic energy is transformed into the thermal energy of the wrecks. What is the temperature increase of each car? You can assume that each car's specific heat is that of iron. Homework Equations...
  7. T

    What has thermal energy but not heat? (and vice versa)

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  8. DaveC426913

    Heat energy and thermal energy

    My editor friend is questioning the following passage in a book. Does this sound right? In particular, they seem to be making a distinction between "heat energy" and "thermal energy".
  9. T

    Calculating Thermal Energy from Passive Solar Heater

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  10. S

    Very basic questions regarding thermal energy and radiation.

    So we were studying about different types of heat transfers, conduction, convection, and finally we learned about radiation, it was sort of confusing, so I am going to write stuff, and hopefully someone can see what i wrote and see if its correct. basically the book says 'Radiation...
  11. T

    Defining Thermal Energy: Understanding the Concept and Its Various Forms

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  12. W

    Programs Which Engineering Major Is Best for a Career in Thermal Energy?

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  13. F

    Convert kinetic energy into thermal energy

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  14. K

    What is the difference between heat and thermal energy?

    Postulate a parcel of air within the larger atmosphere. The air above the parcel is cooler than the parcel, while the air below it is warmer. The parcel is emitting photons to both the overlying and the underlying layers of air and simultaneously absorbing photons from both layers. Both sets...
  15. F

    How much thermal energy it takes to raise the temperature

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  16. A

    Where does the (5/2) come from in calculating thermal energy of diatomic gas

    So I am doing a second year thermodynamics course and would like to know. Do we just have to remember (5/2)PV for a diatomic gas, why is it 5/2 and also what is it for a monatomic gas. Also would we have to remember more complex ratios for exams? Cheers
  17. D

    Thermal energy to be dissipated in an hour

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  18. S

    Is work done by friction the same as thermal energy?

    Homework Statement I ask this because my initial assumption was that work done by a non-conservative force (friction in this case) is also equal to thermal energy. However, in my book, it gave an equation with W = Emec + E thermal. They also had an example where they added up the work and...
  19. C

    Does an object lose thermal energy due to gravity alone

    If I have an object say a 1kg lump of metal. it is at a temperature of say 20c. I then take that object and raise it and place it on a shelf, does it lose any thermal energy due to the new height, In other words does it cool down for no other reason than being raised to a different elevation...
  20. C

    Thermal Energy Transfer: A Gas Heated at Constant Volume and Pressure

    A quartz tube contains one mom of gAs at 20 deg c. The gas is heated at constant volume to 300 deg c. How much thermal energy is transferred to the gas? If the same amount were heated at constant pressure, how muh energy would be required? I know how to solve this for constant volume using E=...
  21. L

    Calorimetry: Thermal energy going into translational KE

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  22. C

    Does steam rising in an insulated tube lose thermal energy

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  23. B

    Thermal Energy vs Heat: Understand the Difference

    According to my textbook... Thermal energy is the kinetic energy of the component particles of an object and is measured in joules. Heat is the thermal energy that is absorbed, given up or transferred from one object to another. But later on the book there is a small chapter called...
  24. X

    Questions about kinetic energy, thermal energy and momentum

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  25. S

    How Much Energy Is Lost to Friction in This Physics Problem?

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  26. K

    Entropy changes: Thermal energy to work and (some) back to Thermal energy

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  27. P

    A calculation on thermal energy from friction.

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  28. O

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  29. U

    Reversible reaction activated only by thermal energy

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  30. E

    How Does Engine Efficiency Affect Cooling System Temperature?

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  31. P

    What Is the Difference Between Temperature and Thermal Energy?

    Hi, :smile: While running, a person generates thermal energy but maintain approximately constant temperature: Distinguish between the terms: Temperature and Thermal Energy I know temperature is a measure of the average Kinetic Energy of molecules but I always get confused when it comes...
  32. K

    What happens when ice is added to water at different temperatures?

    i have a question: In an Insulated Vesse, 250 g of ice at 0 degree Celsius is added to 600 g of water at 18 degree Celsius. Find: a) Final temperature of the system. B) How much ice remains. PLEASE POST THE WAY HOW TO DO THIS QUESTION :D
  33. A

    Thermal energy of a gas in a box

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  34. H

    Thermal Energy to Useful Energy

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  35. W

    Thermodynamics - Thermal Energy of a gas

    Homework Statement The rms speed of the molecules in 1.2 g of hydrogen gas is 1800 m/s. What is the thermal energy of the gas? Homework Equations m = Mass of 1 H molecule: 1.67 x 10^-27 kg N = Total # of molecules = 7.19 x 10^23 molecules c = rms speed The equation provided by my...
  36. M

    By how much does the thermal energy of the gas change?

    This is my very first post... :) I found some help here: https://www.physicsforums.com/showthread.php?t=277092 But I have a difficulty in sloving second and third part Homework Statement The figure shows(check the link) a thermodynamic process followed by 1.90×10^−2 of hydrogen (link to...
  37. H

    Understanding the Difference Between Heat and Thermal Energy

    There seems to be considerable confusion in the scientific community about thermal energy and heat. I have read several textbooks on thermodynamics and several posts in scientific forums and they certainly don't agree on what is heat and thermal energy. For some: thermal energy is the kinetic...
  38. W

    Calculating Thermal Energy of Hot Air Flow

    haw can i calculate the thermal energy (watt or BTU ) of the hot air (or the exhaust air of the chimney) according to the following : Temp. : 250 C hot air flow rate : 11 000 m3/h thanks
  39. D

    Question Regarding Thermal Energy

    Homework Statement An ideal gas is at 20C. The gas is cooled, reducing the thermal energy by 35%, What is the new temperature in C? Homework Equations None in particular. The Attempt at a Solution 35% of 20C is 7, 20-7= 13C
  40. H

    Thermal energy storage and usee

    i want to try use heat energy to power a small device, but i also want to be able to store some energy for use at a later stage... how could i go about doing this? also it needs to be as small as possible, and also very cheap id guess that it could be relatively simple to do considering i just...
  41. A

    Mechanical energy into thermal energy

    Homework Statement the roller coaster is 94.5m high at its highest point. what is the maximum possible speed of the roller coaster? the roller coaster's actual maximum speed is 4.1m/s.what percentage is lost to thermal energy due to friction? Homework Equations Wnc= Efinal-Eintial the part...
  42. S

    How Does Pulling a Chain Affect Its Thermal Energy?

    Homework Statement A chain of metal links with total mass m = 7 kg is coiled up in a tight ball on a low-friction table. You pull on a link at one end of the chain with a constant force F = 52 N. Eventually the chain straightens out to its full length L = 0.8 m, and you keep pulling until you...
  43. C

    Thermal Energy created by block sliding down ramp

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  44. N

    Thermal Energy I don't see why my method is wrong.

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  45. R

    Thermal Energy Transfer in a Boiling Water and Aluminum Pan System

    Homework Statement 140 grams of boiling water (temperature 100° C, heat capacity 4.2 J/gram/K) are poured into an aluminum pan whose mass is 1050 grams and initial temperature 26° C (the heat capacity of aluminum is 0.9 J/gram/K). (a) After a short time, what is the temperature of the...
  46. C

    How Much Thermal Energy is Needed for a Four Month Space Journey?

    Hello! I was wondering if someone could take a look at this idea and tell me if there is something wrong with it: In attempting to shut down every part of a hypothetical spacecraft except some sort of highly insulated crew pod, the total amount of heat produced over a period of time is...
  47. H

    Understanding Thermal Energy: Exploring the Definition and Use of kT in Physics

    I am a first year Physics undergraduate. My question is with regrads to thermal energy. Many people define thermal energy as kT and equate that with the kinetic energy. In other instances, they equate 0.5kT with the kineitc energy. I am thoroughly confused about this. What is thermale...
  48. S

    Difference between heat, thermal energy, and temperature

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  49. F

    Protostar - Thermal energy change

    Homework Statement I have to calculate the change in a protostar's thermal energy \Delta E_{term} on a year. I am given the protostar's luminosity L=3,5\cdot 10^{28}\,W Furthermore I am told that the energy that the star radiates comes from the lost potential energy under the star's...
  50. D

    Thermal energy power station problem

    [b]1. Homework Statement : A power station with an efficiency of 0.3 generates 10^8 W of electric power and dissipates 2.33 multiplied by 10^8 W of thermal energy to the cooling water that flows through it. Knowing the specific heat of water in SI units is 4184 J/kg°C, calculate how many...
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