In this section, Past Mechanics I, you will begin to learn of the many other branches of physics. Already you have learned the laws governing motion. Now, you will learn the laws governing matter, heat, and sound. The areas of study in this section differ from each other, unlike the ones in the Mechanics section. But each of these three diverse areas of study require you to look beyond the obvious, and to learn more about what is not so easily seen.
The application of what you will learn in this section is more subtle, but just as useful, as the application of mechanics. Builders gauge the stresses of beams, and build the most powerful and lightest beams by using the laws of tension and compression. Engineers design aircraft based on Bernoulli's principle, and railroad engines are made from an exact knowledge of heat.