Understanding Thermodynamic Processes in a Piston-Cylinder System

In summary, the conversation involves a problem where a container with a piston and gas undergoes several states with different temperatures and pressures. The initial state has a surface area of the piston of 1.2 x 10^-2 m^2, a temperature of 0 degrees Celsius, a volume of 1.5 x 10^-3 m^3, and a pressure of 1.02 x 10^5 Pa. In state 2, a 150 kg weight is added, causing the piston to go down and the temperature to remain at 0 degrees Celsius. In state 3, the cylinder is brought in contact with boiling water, raising the temperature to 100 degrees Celsius and causing the weight to go up
  • #1
cdhotfire
193
0
Okay, i found this problem to be pretty tough, maybe someone can lend me a hand.

Theres a container with a piston, and there's a gas on the bottom of the piston.

State 1
[itex]A=1.2 x 10^{-2}m^{2}[/itex]
[itex]T_1=0^{\circ{}}C[/itex]
[itex]V_1=1.5 x 10^{-3}m^{3}[/itex]
[itex]P_1=1.02 x 10^{5}Pa[/itex]

State 2
Theres a 150kg weight ontop to the piston, wish causes the piston to go down.
[itex]T_2=0^{\circ{}}C[/itex]

State 3
The cylinder is brought in contact with boiling water raising temperature to [itex]100^{\circ{}}C[/itex]
The weight goes up, the gas pushes up the piston, and the piston pushes up the weight.
[itex]T_3=100^{\circ{}}C[/itex]

State 4
The block is removed, and the gas expands to fill the container, which is a cylinder.
[itex]T_4=100^{\circ{}}C[/itex]

All I need is how to get this started I think I can get it going from there.

The truth is I don't even know how to start this, looked at it for like 30 minutes, maybe I missed something.

But any help would be appreciated.

Thxs.
 
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  • #2
You need to understand the fact that any thermodynamical transformations that take place in the gas (probably assumed ideal) are assumed quasistatical and reversible.So u can apply the law of Mendeleev and Clapeyron.

You didn't say what the problem was asking you... :tongue2:

Daniel.
 
  • #3
Hmm, does not seem I learned those laws, onless my book and teacher are calling them by different names. O, and I asked to get this started, for example finding pressure on state 2. From what I see, is that the 150 kg weight does work on the gas? I might be wrong. But if so it does 1470 J, so I got Work. Work is [itex]\Delta W= P \Delta V[/itex]. I can see that pressure goes up, and volume goes down. But I have no clue as in how to find either of those.
 
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  • #4
O and thank you for replying. :smile:
 
  • #5
cdhotfire said:
Hmm, does not seem I learned those law, onless my book and teacher are calling them by different names. O, and I asked to get this started, for example finding pressure on state 2. From what I see, is that the 150 kg weight does work on the gas? I might be wrong. But if so it does 1470 J, so I got Work. Work is [itex]\Delta W= P \Delta V[/itex]. I can see that pressure goes up, and volume goes down. But I have no clue as in how to find either of those.

That "A" is it the surface of the piston??If so,u can compute the pressure the piston is exeritng on the gas...Temperature remains constant,so you'd have to apply
[tex]P_{1}V_{1}=P_{2}V_{2} [/tex]

Daniel.
 
  • #6
Hmm, I didnt think of that. I think I can take it from here. Thank you very much. :smile:
 

1. What is thermodynamics in action?

Thermodynamics in action refers to the study and application of the laws and principles governing the transfer of energy and its transformation into work in various systems, such as engines, refrigerators, and turbines.

2. What are the laws of thermodynamics?

The laws of thermodynamics are fundamental principles that describe the behavior of energy in physical systems. They include the first law, which states that energy cannot be created or destroyed but can only be transferred or converted, and the second law, which states that the total entropy of a closed system will always increase over time.

3. How does thermodynamics relate to everyday life?

Thermodynamics plays a crucial role in many aspects of everyday life, such as in the functioning of household appliances like refrigerators and air conditioners, the production of electricity, and even in our own bodies during metabolism and digestion.

4. What are some practical applications of thermodynamics?

Some practical applications of thermodynamics include power generation through steam turbines, the production of refrigeration and air conditioning, and the design of efficient engines and vehicles. It is also used in industries such as aerospace, chemical, and environmental engineering.

5. How does thermodynamics impact the environment?

Thermodynamics has a significant impact on the environment, particularly in terms of energy production and consumption. The second law of thermodynamics states that energy conversions are never 100% efficient, meaning that some energy will always be lost as waste heat, contributing to environmental issues such as global warming and air pollution.

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