My professor for classical mechanics has asked that we find some difficult problems in classical and solve them. My first thought was to look through my book for hard problems. However, we are using a free PDF that is rather lackluster when it comes to homework problems. Almost all of the questions are trivial, and amount to solving for the equations of motion once I have set up the Hamiltonian. I have a copy of VI Arnold's Mathematical Methods of Classical Mechanics on hand. Though I haven't had too much time to peruse it for interesting problems, it appears to be hands-off and not provide many problems. I currently know the basics of Hamiltonian's and anything below that. Does anyone have any advice where I can find interesting and sufficiently difficult problems in classical to solve? If anyone has any problems of their own, I would love to hear those too.