I teach myself a lot of topics with textbooks and I love textbooks as well as science. I'm a physics major in college and I can say very confidently that this is the WORST textbook ever. I tried reading the textbook to help learn the content in the class that this textbook was required for, and it made me more lost and the textbook's explanations leaves something to be desired. I've noticed many of the chapter questions in the Practice textbook don't line up to the chronology of the content very well. Many key pieces of knowledge are missing. Mazur gives more equations than you can shake a stick at and for some of the equations doesn't explain important symbols/variables. Other concepts are explained very shallowly. Mazur will give a short example of some of the concepts but won't explain it in much detail. One good example of this is the time constant. He runs on about how even though torque and the time constant have the same symbol, there are not related. He does not, however, go into much detail of what exactly the time constant is or how to approach the concept. He uses a very specific, different notation of writing forces that me nor anyone in my entire class was used to, which ultimately lead to unnecessary conflicts and confusions. For many of the questions my professor assigned for homework, I had to resort to looking equations up on the internet after looking all through both textbooks to help. All in all, the textbook is useless and is a waste of time. My professor has even expressed that he isn't sure if he wants to use this textbook in any future classes. I bought a $3 physics textbook in Goodwill that is 1,000,000 times more informative than Mazur's textbooks.