Collaboration is expected for group activities including projects and group homeworks. Interaction with your group is also encouraged on individual homeworks, however, the final solutions should be worked out individually. Clearly, there should be no interaction during an examination period. Instructions for each assignment should be followed. If in doubt, ask the instructor.
Homework is due at the beginning of class on the assigned due date.
No credit will be given after that. Individual and group assignments will be given, but I always encourage group discussions before solving any problem. Obviously, copied assignments or computer programs are not acceptable.