Final answer:
The cover doors on a diesel-powered MC-7 should remain closed to ensure proper airflow for engine combustion and to maintain optimal engine temperature. This is similar to the effect seen when a plastic bag flies out of a moving car due to differences in air pressure created by airflow.
Step-by-step explanation:
When a diesel-powered MC-7 is operated with the cover doors closed, the internal components of the engine, such as the air intake and cooling systems, can function properly. Cover doors help to ensure that the engine receives the correct amount of airflow for combustion and that the cooling system can maintain an optimal engine temperature. The principles behind this can be illustrated by understanding why an empty plastic bag flies out of an open car window. When a car is moving, air flows over the body of the car and creates an area of low pressure inside the vehicle. Lowering a window disrupts this airflow, causing higher pressure air from outside to rush into the car, resulting in the lighter objects like plastic bags being carried away with the moving air.