Difference Between Open and Closed Systems Regarding Energy

Question

Hey everyone! 👋 Physics can sometimes feel like navigating a maze, especially when we're talking about tricky concepts like open and closed systems. I always struggled to keep them straight! Let's break down the difference between open and closed systems regarding energy transfer. I hope this helps clarify things! 😊

ericaharris1996 · Accepted Answer

📚 Introduction to Open and Closed Systems
In thermodynamics, a system refers to a specific region of space or a quantity of matter that we're interested in studying. The rest of the universe outside the system is called the surroundings. Systems can interact with their surroundings by exchanging energy and matter. Open and closed systems are defined by the types of exchanges they allow.

🚪 Definition of an Open System
An open system is a system that can exchange both energy and matter with its surroundings. Think of it like an open door; things can freely come and go.

🔒 Definition of a Closed System
A closed system is a system that can exchange energy with its surroundings, but it cannot exchange matter. Imagine a sealed container; heat can get in or out, but nothing inside can physically escape.

📝 Open vs. Closed Systems: A Detailed Comparison

Feature
      Open System
      Closed System

Exchange of Matter
      ✅ Allowed
      ❌ Not Allowed

Exchange of Energy
      ✅ Allowed
      ✅ Allowed

Examples
      Boiling pot of water (without a lid), a living organism, an internal combustion engine
      Sealed container with hot coffee, the Earth (to a limited extent, neglecting space debris), a battery

Mass
      Variable
      Constant

Energy Transfer Modes
      Heat, work, mass flow
      Heat, work

Mathematical Representation
      Complex due to variable mass, often involves control volume analysis
      Simpler due to constant mass, can often be analyzed using the first law of thermodynamics: $ \Delta U = Q - W $ (where $\Delta U$ is the change in internal energy, $Q$ is the heat added, and $W$ is the work done)

Equilibrium
      Achieves equilibrium with surroundings by exchanging both energy and matter
      Achieves equilibrium with surroundings by exchanging only energy

✨ Key Takeaways

🌍 An open system exchanges both energy and matter with its surroundings, exemplified by a boiling pot without a lid. 
     🌡️ A closed system exchanges only energy but not matter, such as a sealed container of hot coffee. 
     💡 The key difference lies in whether matter can enter or leave the system. 
     🔢 Mathematical models for closed systems are often simpler due to the constant mass, allowing direct application of the first law of thermodynamics.
     ⚙️ Understanding these systems is crucial for analyzing various physical and chemical processes in engineering and science.

Difference Between Open and Closed Systems Regarding Energy

1 Answers

📚 Introduction to Open and Closed Systems

🚪 Definition of an Open System

🔒 Definition of a Closed System

📝 Open vs. Closed Systems: A Detailed Comparison

✨ Key Takeaways

Join the discussion

Feature	Open System	Closed System
Exchange of Matter	✅ Allowed	❌ Not Allowed
Exchange of Energy	✅ Allowed	✅ Allowed
Examples	Boiling pot of water (without a lid), a living organism, an internal combustion engine	Sealed container with hot coffee, the Earth (to a limited extent, neglecting space debris), a battery
Mass	Variable	Constant
Energy Transfer Modes	Heat, work, mass flow	Heat, work
Mathematical Representation	Complex due to variable mass, often involves control volume analysis	Simpler due to constant mass, can often be analyzed using the first law of thermodynamics: $ \Delta U = Q - W $ (where $\Delta U$ is the change in internal energy, $Q$ is the heat added, and $W$ is the work done)
Equilibrium	Achieves equilibrium with surroundings by exchanging both energy and matter	Achieves equilibrium with surroundings by exchanging only energy