After finishing the block of code around page 294, I should be able to build and run in order to test the hook. Currently, tapping on the spring launches the cat, but the cat never hooks and the level fails. I checked the finished version from the example folders, but it has the same problem as well. I am learning physics with this book, so I am unsure where the error is, especially when the finished example game also fails.
Edit: I just saw there is a newer version of the book, 1.3, which I downloaded and ran. The CatNap level 2 hook works properly in the newer version, so I will go thru that to figure out the difference between it and the 1.2 version I was using.