Energy transfers occur constantly in daily activities. Think...

Name: Problem 61, Chapter 6: Biology for AP Courses
Uploaded: 2020-11-11T15:54:15-08:00
Duration: 3 min 1 s
Channel: Caitlin Boucha
Description: Energy transfers occur constantly in daily activities. Think of two scenarios: cooking on a stove and driving a car. For each scenario, describe the system and explain how the second law of thermodynamics applies to the system in terms of energy input and change in entropy

Energy transfers occur constantly in daily activities. Think of two scenarios: cooking on a stove and driving a car. For each scenario, describe the system and explain how the second law of thermodynamics applies to the system in terms of energy input and change in entropy

Key Concepts

Thermodynamic Systems

A thermodynamic system is a defined portion of the universe that is isolated for the analysis of energy exchanges with its surroundings. This concept involves clearly delineating the boundaries to distinguish between what is included in the system and what constitutes its environment, enabling systematic study of the energy transfers and transformations occurring within the system.

Energy Transfer

Energy transfer refers to the movement of energy from one part of a system to another or between different systems. This movement can occur in various forms, such as heat, work, or internal energy, and is a fundamental factor in analyzing how systems perform tasks, whether it’s the conduction of heat in cooking or the conversion of chemical energy to mechanical work in a car.

Second Law of Thermodynamics

The Second Law of Thermodynamics states that in any natural thermodynamic process, the total entropy of an isolated system will tend to increase over time, meaning that processes occur in a direction that increases disorder. This principle explains why energy conversions are never completely efficient, as some energy is always dissipated as unusable heat, contributing to an overall increase in entropy.

Entropy

Entropy is a measure of the randomness or disorder within a system. It quantifies the number of ways energy can be distributed among the molecules of a system, and according to the second law, energy transfers typically result in an increase in entropy, indicating a spontaneous move towards greater disorder in energy dispersal.

Transcript

00:01 Okay, so we are answering a question about the second law of thermodynamics, which deals with the quality of energy.

00:06 But first we're going to kind of want to think about the first law of thermodynamics.

00:09 So the first law of thermodynamics states that delta u, excuse me, delta u is equal to q minus w.

00:20 Delta u being the change in internal energy, q is heat, w is the work done by the system.

00:45 And what is this saying? it's the saying that energy, that heat energy cannot be created or destroyed.

00:51 It is always going to be in some form.

00:56 Right.

00:56 So then we want to go over to the second law of thermodynamics here now.

01:00 And the second law is stating that we're dealing with the quality of the energy.

01:04 And the quality of the energy can mean any number of things that it could be the the heat from the pan when you're cooking.

01:13 It could be the gasoline being burned.

01:16 So we're actually going to use those examples here.

01:18 So when we cook food on the stove, so this is my pan.

01:27 I am not an artist.

01:28 I will point that out right now.

01:29 This is my pan.

01:30 Here's my stove...

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