What must happen to the doors when the car of an automatic elevator leaves the floor?

When the car of an automatic elevator leaves the floor, the doors must automatically close to ensure safe and efficient operation. This automatic closure prevents passengers from accidentally entering or exiting the elevator while it is moving, which is crucial for safety. It also helps to maintain the system's efficiency by ensuring that the elevator is ready for operation as soon as it arrives at the next floor.

The automatic closing feature is a standard safety requirement in elevator design to minimize risks associated with open doors, particularly in a busy environment where quick and orderly transport is necessary. This action supports compliance with safety codes and regulations that govern elevator operation, emphasizing the importance of preventing unnecessary accidents.