December 3, 2022
The Physics of Everyday Stuff


One of my favorite books as a kid was The Way Things Work by C Van Amerongen (Simon and Schuster), which my parents gave to me for Christmas one year. This book describes how all sorts of things are put together. Since I spent a lot of time taking things apart to figure out how they worked, my parents had damage control partly in mind in giving me the book. I, on the other hand, was particularly happy about seeing assembly drawings of things I couldn't get my hands on, like jet engines, or that were small and hard to figure out, like a phonograph cartridge.

The Way Things Work is a wonderful source if you want to see how everyday things are constructed, and I highly recommend it. However, it does not describe the underlying physics principles involved in a given device. Most of the things we use in our modern, technological society are based on a few, basic concepts of physics. This reflects the goal of physics: to describe natural laws, experimentally studied, with a basic set of widely-applicable concepts. The goal of this web book is demonstrate this broad applicability to a wide variety of things we experience every day.

Traditional introductory physics courses are tought subject by subject, in a roughly historical order. You start with kinematics (the mathematical description of motion), move on to dynamics (the laws relating motion to forces), then thermodynamics (laws relating energy, heat and temperature), then electricity and magnetism, usually a little optics, and wind up with atomic physics (mainly the interaction of light and atoms). This takes a school year, and you're best off having a few calculus courses under your belt before you start so you can use calculus in the physics class. This is clearly a big project.

This web book takes a different approach --- rather than describing the laws of physics and concocting examples along the way, as you do in a physics course, it takes examples from everyday life and describes the relevant physics. Of course, it makes sense to start with simpler physics and build up to more complicated things. If you read the web book from front to back, you will be introduced to new physical concepts in an orderly fashion. If you use this web book as a reference, you may have to look back at previous examples to fill in some of the physics, and it's cross-referenced for that reason.

It is very difficult to discuss physics quantitatively without using some mathematics. I assume that you know some algebra and trigonometry, but may not know or remember calculus. Since calculus was, in fact, developed for use in physics, I will mention where it comes in from time to time.

The various topics all stand on their own, but if you'd like to see them categorized, here are the general areas that they fall under:

  1. The Shotput (translational dynamics)
  2. Icebergs (buouyancy)
  3. Skidmark Forensics (friction and translational dynamics)
  4. Gun Recoil (translational dynamics)
  5. Figure Skating Spins (rotational dynamics)
  6. Swings (rotational dynamics)
  1. Transmission Lines (basic circuits)
Waves and Sound
  1. The Guitar (Sound)

I haven't worked on this site for many, many years, but I think now that I've moved it to a new server I may start adding some new topics. Send me an email if you have a suggestion!