Introduction to Biological Physics for the Health and Life Sciences

Kirsten Franklin, Paul Muir, Terry Scott, Paul Yates

• Publisher: Wiley
• Year: 2019
• ISBN:
  9781118934487
• Edition: 2
• Topic: Physical Sciences
• Subtopic: Physics
• Index: Physics

A thoroughly updated and extended new edition of this well-regarded introduction to the basic concepts of biological physics for students in the health and life sciences.

Designed to provide a solid foundation in physics for students following health science courses, the text is divided into six sections: Mechanics, Solids and Fluids, Thermodynamics, Electricity and DC Circuits, Optics, and Radiation and Health. Filled with illustrative examples, Introduction to Biological Physics for the Health and Life Sciences, Second Edition features a wealth of concepts, diagrams, ideas and challenges, carefully selected to reference the biomedical sciences. Resources within the text include interspersed problems, objectives to guide learning, and descriptions of key concepts and equations, as well as further practice problems.

NEW CHAPTERS INCLUDE:

• Optical Instruments
• Advanced Geometric Optics
• Thermodynamic Processes
• Heat Engines and Entropy
• Thermodynamic Potentials

This comprehensive text offers an important resource for health and life science majors with little background in mathematics or physics. It is also an excellent reference for anyone wishing to gain a broad background in the subject.

Topics covered include:

• Kinematics
• Force and Newton's Laws of Motion Energy
• Waves Sound and Hearing
• Elasticity
• Fluid Dynamics Temperature and the Zeroth Law
• Ideal Gases Phase and Temperature Change
• Water Vapour
• Thermodynamics and the Body Static Electricity
• Electric Force and Field
• Capacitance
• Direct Currents and DC Circuits
• The Eye and Vision Optical Instruments
• Atoms and Atomic Physics
• The Nucleus and Nuclear Physics
• Ionising Radiation
• Medical imaging
• Magnetism and MRI

Instructor's support material available through companion website, www.wiley.com/go/biological_physics

III
Thermodynamics

Thermodynamics is the study of thermal energy, its movement, and its transformation. In the following chapters, we will develop a quantitative understanding of thermal energy, heat and temperature, and how thermal energy is exchanged between different systems, especially the body. We will also focus on how these concepts are important for understanding human metabolism and how we interact with our environment. The human body operates within only a narrow temperature range because the rates of the biochemical reactions that sustain our lives, and the conformation of the many proteins in our bodies, rely on this. In this topic, we will look at the regulatory processes that keep our core body temperature constant despite the changes in our external environment.

The first six chapters in this section will cover the introductory topics in thermodynamics which are of central importance in the health sciences. These chapters will introduce: the fundamental concepts of temperature, thermal energy, and thermal equilibrium; ideal gases; the relationship between temperature and states of matter; the properties of water-vapour/air mixtures; the transfer of heat between systems and the factors that affect it; and how these things are relevant to the human body.

The last three chapters in this section will introduce some more advanced material. These ideas are of central importance in chemistry and biochemistry as well as in other areas of science. The concepts covered in these chapters include: the idea of a thermodynamic process; heat engines; entropy and the second law of thermodynamics; enthalpy; Helmholtz energy; Gibbs energy; and the chemical potential. It is expected that these chapters will be used primarily for reference after the completion of a first course in physics.

17
Temperature and the Zeroth Law

1. 17.1 Introduction
2. 17.2 Thermal Equilibrium
3. 17.3 Measuring Temperature
4. 17.4 Thermal Expansion of Materials
5. 17.5 Summary
6. 17.6 Problems

17.1 Introduction

Temperature is an important property for the body because it is a sensitive indicator of health status. In this chapter, we will introduce the concept of temperature by looking at temperature scales, temperature measurement, and how materials expand and contract in response to temperature changes.

Key Objectives

• To develop an understanding of temperature and how we measure it.
• To understand the concept of thermal equilibrium.
• To be able to calculate amounts of thermal expansion.

17.2 Thermal Equilibrium

Defining Temperature

Temperature is a measure of how hot or cold something is. There are several ways to describe what temperature is; a good starting point for understanding is from the laws of thermodynamics. The law that defines temperature was not identified as such until after the other laws of thermodynamics, but was considered in many ways to be more fundamental, so it has become known as the zeroth law.

First, we need to take a look at the concept of thermal equilibrium. When two systems are in equilibrium, they are balanced in some way: they share a property. When systems are in thermal contact, they exchange energy until an equilibrium state is reached, and no more net energy transfer occurs. The zeroth law of thermodynamics states it in this way:

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Key concept:

If two systems, A and B, are in thermal equilibrium, and a third system, C, is in thermal equilibrium with A, then it is also in thermal equilibrium with B. The property that the systems share is called temperature.

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When we use a thermometer, we place it in contact with an object and allow it reach thermal equilibrium so it has the same temperature as the object. We can therefore say, for all practical purposes, temperature is what a thermometer reads.

Thermal En...