Answer: 
Following are the examples of 'physical systems': 
The Amazon rain forest, the Gulf Stream and the San Andreas fault. 
Step-by-step explanation: 
- In the discipline of Geography, a physical system is one that has a few natural characteristics and specifications of its own, has a defined natural procedure of functioning, and moreover, it interacts with the surrounding environment naturally. 
- Thus, the Lincoln Tunnel and the California Gold Mine do not make a physical system as far as the subject matter of Geography is concerned.