How to Find Final Temperature with Constant Pressure and Changing Volume

In summary, 645 J of heat is transferred to 0.185 mol of air at initial pressure of 3.00E6 Pa and temperature 780K inside a cylinder with volume 0.40 L. The final temperature can be found by using the equation W=p(V2-V1) and solving for V2 using dE=Q-W, assuming pressure remains constant.
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Homework Statement


645 J of heat is transferred to 0.185 mol of air inside a cylinder with volume 0.40 L. The air is at initial pressure is 3.00E6 Pa and temperature 780K.

Find the final temperature if the cylinder volume is allowed to increase while pressure remains constant.

Homework Equations


W=p(V2-V1)

The Attempt at a Solution



I have literally no idea how to do this problem. The examples in the book are (once again) unlike this problem. The question doesn't even make sense. It doesn't say what the final volume is.
 
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If the pressure remains constant, you know whatever work the cylinder does is given by W=p(V2-V1). Can you use dE=Q-W to solve for V2?
 

FAQ: How to Find Final Temperature with Constant Pressure and Changing Volume

What is the purpose of a piston in thermodynamics?

A piston is a device used to convert energy from heat into mechanical work in a thermodynamic system. It is typically a cylindrical component that moves back and forth within a cylinder, creating a force that can be used to power machinery or perform other tasks.

How does a piston work in a thermodynamic system?

A piston works by being enclosed in a cylinder that is connected to a heat source. When heat is applied to the cylinder, it causes the gas or fluid inside to expand, pushing the piston outward. The piston is then connected to a crankshaft, which converts the linear motion of the piston into rotational motion that can be used to power machinery.

What is the relationship between a piston and the first law of thermodynamics?

The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted from one form to another. In the case of a piston, the heat energy from the heat source is converted into mechanical work, demonstrating the first law of thermodynamics in action.

How does the size of a piston affect its performance in a thermodynamic system?

The size of a piston can greatly impact its performance in a thermodynamic system. A larger piston will have a larger surface area, allowing it to exert more force and do more work. However, a larger piston may also require more energy to move, so the size must be carefully chosen based on the specific needs of the system.

What are some real-world applications of the thermodynamics of a piston?

Pistons are used in a wide range of real-world applications, including internal combustion engines, pumps, compressors, and refrigeration systems. They are also used in industrial machinery such as presses and cranes, as well as in smaller devices such as bicycles and air pumps.

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