UNDERSTANDING PHYSICS
Professor of Physics at A. Mickiewicz University Poznan, Poland
Physics is a very interesting branch of science. Yes, it
really is. The only requirement for this statement to be true is that you
understand the laws of physics. Once you understand them you will find physics
not only interesting, but very useful. The aim of this tutorial, or kind of
textbook of physics, corresponds with its title. The explanations of any
physics problem in this tutorial start at elementary school level and continue
to University student level. At any stage of studying the problem in this
tutorial you can jump to more advanced explanations, skipping information you
are already familiar with. Such a structure makes this tutorial more universal.
There are numerous exercises and problems at the end of each chapter, some of them solved, some left as “homework” assignments. This should help in understanding physics and makes these Web pages the equivalent of a complete textbook - theory + exercises.
It is an ambitious project to prepare such tutorial or, if you prefer, encyclopedia, or to put it even differently, a kind of online textbook of physics. Building it requires time. As I am still an active teacher at the University, I can only spare a few hours a week for composing this tutorial. In such circumstances completing this task will take some time. Therefore I will put new additions on the site as I write them. This means that each time you enter these pages there will be a little more things to study. All kinds of comments are welcome and every part of this tutorial may become better thanks to your feedback.
Most things which we see around us are governed by laws of Physics. Much more things and phenomena we do not see, as they are “hidden” inside molecules or atoms, are also governed by these laws.
We start explaining all this in the part of Physics generally known as Mechanics. It is the traditional, probably the best, way that all the textbooks start. In Mechanics we deal with phenomena everyone can observe during their everyday life. We see cars accelerating and stopping, we work hard climbing stairs, we use a knife for cutting our steak in a restaurant, and we see hundred of other things which require the knowledge of physics to explain why and how they happened.
To make any explanation we need units to describe and measure things or phenomena. Throughout all this tutorial we will use
The International System of Units
(abbreviated as SI).
For detailed description of this system you are invited to visit the
web page of National Institute of Standard and Technology
. Of course you will find all necessary definitions connected with
SI system in this textbook too. This will be done successively in connection
with Physics problems presented.
The best way to understand physics is trough solving problems and exercises. We will add them to each theoretical description of the topic. There will be numerous problems solved step by step and this should help you in reaching a deeper understanding of Physical laws and different phenomena governed by these laws.