Heating a room and internal energy question

In summary: P.: "Hi, I am having a hard time answering this question. Any help will be appreciated."In summary, Chetan P. is seeking help with a question related to a paper published in 1938 in the journal Nature titled "Why do we have winter heating?" The paper discusses the assertion that heating a room does not increase the total internal energy of the room, assuming the room is filled with an ideal gas, the volume is fixed, and the pressure is variable. Chetan P. asks for an explanation of how the internal energy of the room is affected by temperature and how this relates to changes in state variables.
  • #1
sbdavinci
1
0
Hi, I am having a hard time answering this question. Any help will be appreciated.
In 1938, the journal Nature published a paper by R. Emden titled “Why do we have winter heating?” (Nature Vol 141 pp. 908-9 – although you do not need to read it to answer the problem). This article asserts that heating a room does not increase the total internal energy of the room. Examine this assertion assuming:

(a) the room is filled with an ideal gas
(b) the volume of the room is fixed
(c) the pressure of the room is variable and set by the external atmosphere.
(i) Show that the internal energy of the room is independent of the temperature of the room!
(ii) What state variables change with temperature in order to maintain constant internal energy? How are they affected by temperature (derive an equation to describe this)?

Thank you
 
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  • #2
Based on the assumptions for constant values in the statement: If you rearrange the ideal gas equation to substitute the variable terms in the formula for internal energy, maybe you are able to see how the internal energy changes with varying temperature.
 
  • #3
If the temperature rises by ΔT, what is the change in the internal energy per mole? If the temperature rises by ΔT, what is the change in the number of moles of gas in the room?

Chet
 

1. How does heating a room increase its internal energy?

When you heat a room, you are providing energy in the form of heat to the particles that make up the air and objects in the room. This causes the particles to vibrate more quickly, increasing their kinetic energy, which in turn increases the room's internal energy.

2. Why is it important to consider internal energy when heating a room?

Internal energy is an important factor to consider when heating a room because it determines the room's temperature and overall comfort level. The higher the internal energy, the warmer the room will be. Additionally, understanding the internal energy of a room can help you determine the most efficient way to heat it.

3. How is the internal energy of a room affected by its size and shape?

The size and shape of a room can affect its internal energy by changing the surface area and volume of the room. A larger room with more surface area will require more energy to heat compared to a smaller room with less surface area. Similarly, the shape of the room can affect how efficiently the heat is distributed throughout the space.

4. Is it possible to change the internal energy of a room without using heat?

Yes, it is possible to change the internal energy of a room without using heat. This can be done by adding or removing objects in the room, such as opening a window to let in cool air or using a fan to circulate the air. Changes in the air pressure or humidity can also affect the internal energy of a room.

5. How can the internal energy of a room be measured?

The internal energy of a room can be measured using a thermometer, which measures the temperature of the room. This temperature can then be used to calculate the internal energy of the room using the formula Q=mCΔT, where Q is the change in internal energy, m is the mass of the air in the room, C is the specific heat capacity of air, and ΔT is the change in temperature.

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