What is the sign of the work done on the system and by the system?
1) Positive when work is done on the system and negative when work is done by the system
2) Negative when work is done on the system and positive when work is done by the system
3) Positive when work is done on the system and positive when work is done by the system
4) Negative when work is done on the system and negative when work is done by the system