Final answer:
Emergency generators in buildings typically require enough fuel for 24 hours of operation. To power a 4.00-kW device, 40 people each producing 100 W of power would be needed. Replacing an 800 MW power plant would hypothetically require 8 million people, underscoring the power plant's large output.
Step-by-step explanation:
The question regarding the duration that a building with emergency generators must have fuel for does not have a universal answer, as it might depend on regulations, building codes, and specific use cases of the building. However, building codes and safety guidelines commonly require emergency generators to have enough fuel to operate for a certain period of time during power outages. Typically, a time frame like 24 hours is a standard requirement, ensuring that vital systems can continue to function until power is restored or additional fuel can be obtained.
To illustrate the concept of energy requirements, let's consider a scenario where a person in good physical condition can output 100 W of power continuously. To determine how many people it would take to run a 4.00-kW electric clothes dryer, we would divide 4,000 W (the power requirement of the dryer) by 100 W (the power output per person), which results in 40 people needed for the task. For a more substantial example, replacing a large 800 MW electric power plant would require a massive amount of human power. Dividing 800,000,000 W (the output of the power plant) by 100 W (the output per person) shows that it would take 8 million people to replace the power plant's output.