(Hopefully) simple thermodynamics question

In summary, when you compress an ideal gas by pushing down on the piston, the temperature of the gas increases. This is because work is done on the gas, increasing its internal energy. Since the energy of an ideal gas is dependent on its temperature, the temperature also increases. This can be compared to hitting a tennis ball with a racket, where the impact increases the kinetic energy of the ball.
  • #1
AxiomOfChoice
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Suppose you have a piston of ideal gas that's thermally isolated from its surroundings. You compress the gas by pushing down on the piston. Question: Does the temperature of the gas change, and why?

My answer: YES, it changes. Since [itex]\Delta U = Q + W[/itex], and work was done ON the gas (by compressing it), [itex]\Delta U > 0[/itex]. Since the energy of an ideal gas is only dependent on the temperature of the gas, this implies [itex]\Delta T > 0[/itex].
 
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  • #2
Yes, it is increasing because with the piston you increase the momentum of the molecules that are bouncing of it, increasing their speed and with that their kinetic energy, that is like hitting a tennis ball with a racket.
You see the equation in the right way.
 

FAQ: (Hopefully) simple thermodynamics question

1. What is thermodynamics?

Thermodynamics is a branch of physics that deals with the study of energy and its transformations, particularly in relation to heat and work.

2. What are the laws of thermodynamics?

The laws of thermodynamics are fundamental principles that govern energy and its behavior. The first law states that energy cannot be created or destroyed, only transferred or converted. The second law states that the total entropy of a closed system will always increase over time. The third law states that the entropy of a pure, perfect crystal at absolute zero temperature is zero.

3. What is the difference between heat and temperature?

Heat is a form of energy that is transferred from one object to another due to a temperature difference. Temperature, on the other hand, is a measure of the average kinetic energy of the particles in a substance.

4. How is thermodynamics applied in real life?

Thermodynamics has many practical applications in everyday life, including in the design of engines, refrigerators, and air conditioners. It is also used in the study of weather patterns and climate change, as well as in the production of electricity and other forms of energy.

5. What is the difference between an open and closed system in thermodynamics?

An open system is one that can exchange both matter and energy with its surroundings, while a closed system can only exchange energy. Closed systems are typically used in thermodynamics to simplify calculations and make predictions about the behavior of a system.

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