In section 4 we cover the most important topic in the course - modal analysis. We’ll spend plenty of time here making sure you understand concepts like mode shapes, orthogonality and what it means to uncouple the equations of motion. You’ll see that modal superposition as a solution strategy offers us major advantages over the direct integration we discussed in the previous section. By the end of this section, you’ll have a deep understanding of modal analysis and be comfortable implementing it.