Lecture notes, problem sets, and other resources from real MIT classes.
Various past exams from the USAPhO selection cycle.
Lectures by renowned physicist Richard Feynman while a professor at Caltech.
Past examinations for the AAPT PhysicsBowl competition.
Past examinations from the Princeton University Physics Competition.
A valuable resource for F=ma and USAPhO solutions as well as worked out problems from various other resources such as famous physics textbooks.