Question

a house is a system. which of the following is an input to this system? the house heats up; the furnace is turned on; the house cools down; a person looks at the house

Explanation:

To determine the input to the house system, we analyze each option:

• "The house heats up" is an output (the result of the system's operation, like heating).
• "The house cools down" is also an output (a change in the house's state, a result).
• "A person looks at the house" is an external observation, not an input that affects the house system's operation.
• "The furnace is turned on" is an action that provides energy (heat) to the house system, acting as an input to make the house heat up.

Answer:

The furnace is turned on