This book is short (88 pages) and to to the point. It's a great companion to a book like "2D Graphics Programming for Games".
By focusing on the math (geometry and trig) in addition to the code, this is ideal for a University course when there is an expectation that students learn more than simply "application". It's also a great reference book for a coder's bookshelf.
This is not a complete book on "game physics", but only on the most difficult aspect of a physics engine, collision detection. So, if you to quickly add physics to your 2D game, just download one of the open-source physics engines. But if you're actually hoping to strip away the magic and learn something, this is a nice and succinct book covering the topics of 2D collision detection.
When you're ready for 3D and want a stop-by-step on how to build a 3D game engine. Check out "Game Physics Engine Development" by Ian Millington.