Repost - Please, need to get done by tomorrow, stuck big time

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In summary, reposting is the act of sharing something that has been previously shared before, typically on social media platforms, in order to reach a wider audience or remind those who may have missed it. The urgency in the request to repost may be due to a deadline or time-sensitive nature of the content, and if the repost is not done in time, it may miss the opportunity to reach the intended audience or achieve the desired outcome. The platform and format for reposting can vary, but the person requesting the repost may specify their preferences. While the repost can be done by anyone with permission and proper credit, it is advisable to check with the original poster before reposting.
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ChronicQuantumAddict
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Please help with the following question, completely lost:
The behavior of a four stroke gasoline engine can be approximated by the so-called Otto cycle. The process is as follows (6 steps):

1) Isobaric Intake (from V=0) at atmospheric pressure up to volume V1 (maximal volume), Temperature T1

2) Adiabatic compression to volume V2, Temperature T2

3) Isochoric increase of Temperature during ignition to T3

4) Adiabatic expansion to V1 (max volume), Temperature T4

5) Isochoric decrease of temperature (to T1)

6) and Isobaric exhaust to V=0 at atmospheric pressure.


Sketch the process in a P-V diagram. Assume the working substance is an ideal gas and calculate the efficiency of the process. Express the result in terms of the temperatures T1, T2, T3, and T4. If the compression ratio is given by r = V1/V2, express the efficieny with r. For an Engine with r = 8, and gamma = 1.5 what do u obtain? (Note gamma is the ratio of specific heats, Cp/Cv).


siddharth said:
Efficiency is going to be (Net work done by the system)/(Total Heat supplied to the system).
So, you have to express the net work done and total heat supplied in terms of the known quantities.
Try calculating the heat supplied to or lost from the system in each step. Since change in the net Internal energy is zero for the whole cyclic process, if you can find the heat supplied to or lost from the system in each step, you can easily find the work done for the whole process.


I was able to graph the thing. Now i need to know how to calculate the heat in between each step, i am clueless as how to do this. i know once i get that, i can easily find the total work, and i know the expression for the efficiency and everything else.

My main problem is how do u get the heat of each step, and i do know that some steps have no heat exchange. please help, this is due tomorrow, and i may have to post it on the board in class.

Thanks very much
 
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Do not double post and read the FAQ
 
  • #3
You've already been helped in your original thread.
 

1. What is the purpose of reposting?

The purpose of reposting is to share something that has been previously shared before, usually on social media platforms. This allows the content to reach a wider audience or to remind those who may have missed it the first time.

2. Why is there a sense of urgency in the request to repost?

In this case, the urgency may be due to a deadline or time-sensitive nature of the content. The person may need the repost to be done by tomorrow to meet a specific goal or to ensure that the content is relevant and timely.

3. What can happen if the repost is not done in time?

If the repost is not done in time, it may miss the opportunity to reach the intended audience or to achieve the desired outcome. It can also result in the content being outdated or irrelevant, making the repost ineffective.

4. Is there a specific platform or format for reposting?

The platform and format for reposting may vary depending on the type of content and the intended audience. It could be through social media, email, or other online platforms. The person requesting the repost may specify the preferred platform or format.

5. Can the repost be done by someone else or does it have to be done by the original poster?

The repost can be done by anyone as long as they have permission from the original poster and give proper credit. However, it is best to check with the person requesting the repost to ensure they are comfortable with someone else reposting their content.

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