Online resources
In addition to open source physics engines and books, online resources are also a great place to research game physics. There are several blogs and publications available. I highly recommend publications from valve:
- http://valvesoftware.com/company/publications.html
- http://allenchou.net/game-physics-series
- http://randygaul.net/category/physics
- http://gafferongames.com/game-physics
- http://wildbunny.co.uk/blog/category/physics-2
- http://chrishecker.com/Rigid_Body_Dynamics
- http://www.xbdev.net/physics/index.php
- http://brm.io/game-physics-for-beginners
In addition to the mentioned blogs, there are several videos and presentations on various physics topics available on the GDC vault:
There is also a list of relevant GDC presentations hosted on the Box2D website at http://box2d.org/files.
Of course, everyone runs into issues writing code, and physics is an especially difficult topic. If you run into issues with your physics engine, you can always ask for help at...