The National Center for Case Study Teaching in Science is an excellent resource hosted by the University at Buffalo and supported by the National Science Foundation.
The site has a variety of case studies to use in teaching science. Case studies are excellent ways to learn both concepts and content along with process skills and critical thinking. The cases are based on contemporary science problems so they are more relevant to the students.
The cases can be used by the teachers in different ways including classroom discussions and problem/project based learning. The cases are searchable by keyword, subject, and level.
The case studies have been peer reviewed and there are teacher resources available. Each case has objectives, and abstract, teaching resources, and answer key. People also comment on cases, adding tips or ideas. You can also download the entire case in PDF form.
This is another great resource for educators to use in their science classrooms.
Here are some cases that came up when I searched for "Physics"