xkcd: Physics for Entertainment

Physics for Entertainment was written by Yakov Perelman in the 1920’s (in Russian) and updated periodically through the 1930’s. There are actually two parts to it, but Volume 1 is long out-of-print (though findable online — more on that later). The book I have is a 1975 translation of Volume 2. The book is a series of a few hundred examples, no more than one or two pages each, asking a question that illustrates some idea in basic physics.