This is a physics hypertextbook: it is intended as a vehicle for students in the biological and chemical sciences, enabling them to understand the physical underpinnings of their later studies. As often as possible, the systems under investigation will relate to human physiology, for there is no substitute for relevance to motivate the study of a subject. We will address questions like:

- How do we compute protein masses?
- What are the stresses on the skeletal system?
- When might one expect turbulent blood flow?
- How does the speed of nerve impulse propagation depend on axon geometry?
- How does magnetic resonance imaging work?
- How does cellular respiration contribute to entropy generation?
- How does the body regulate its temperature?
- What is the physics of sight?

But while the topics presented here have been chosen for their application to the health sciences, the emphasis is always on learning how the physics of the system affects its chemical and biological behavior.

**There are two activities essential to the study of physics: measurement and prediction**. Experimentation provides us with a measured, ie., quantitative description of how a system behaves. Theory provides a mathematical framework in which to interpret the measurements and predict the behavior of like systems. It is possible, in fact necessary, to describe nature qualitatively, for there we find the link to our verbal and visual world, the world of our interpreted senses. But in the application of mathematics to physical phenomena we find the tools necessary to understand the world in sufficient detail to manipulate it, for good or ill.

We begin our study of physics by establishing the mathematical framework in which most of our predictions will be made. We will add to this framework as necessary, intending for this course that mathematics function in service of the study of physics, and not be explored for its own sake. But the ideas presented in this introductory chapter are essential for the material that follows: if after this course you have only a solid understanding of why this information is useful, and how to apply it to solve problems, you will have the faculties essential to understanding the universe in which you live.

The only background required for this course is a mathematical one. The student of physics must be capable with algebra, because we will solve many equations during our studies. It may even be correct to say that you will actually **learn **algebra while studying physics, because this may well be the first time you have ever had to use it outside of the typically sterile environment of a mathematics course. It is expected that you also have some comfort with the metric system, and can manipulate the basic concepts of area, volume, density, etc. We will also be using right triangle trigonometry, and you should review it if you have not used it for a while.

The first section is about dimensions and units.

If you have stumbled on this page, and the equations look funny (or you just want to know where you are!), see the College Physics for Students of Biology and Chemistry home page.

©1996, Kenneth R. Koehler. All Rights Reserved. This document may be freely reproduced provided that this copyright notice is included.

Please send comments or suggestions to the author.