Final answer:
Regardless of the lever's arms lengths, the work done remains 600 Joules as energy required to lift the box to a certain height is constant.
Step-by-step explanation:
The work done by a lever does not depend on the length of the arms; it is entirely determined by the energy transferred. In the scenario provided, 600 Joules of work is done to lift a box to a height of six meters without the lever. Since the work (energy) required to lift an object to a certain height is constant regardless of the process used, using a lever with an effort arm of 12 meters and a load arm of 6 meters would still result in 600 Joules of work done. Levers can make tasks easier by reducing the force needed, but the total work done remains the same.