Question

On a hot summer day, a student turns his fan on when he leaves his room in the morning. When he returns in the evening, will the room be warmer or cooler than the neighboring rooms? Why? Assume all the doors and windows are kept closed.

Answer 1

Answer:

When the student returns, it will be hotter

Explanation:

We know that the room is closed, so no air is coming in from outside and no air goes outside as the windows and doors are closed. We know the fan is moving and the fan does not cool the air, it only moves the air. Therefore, this process creates kinetic energy that is converted into heat energy (internal) so that room begins to get warmer.

And we know by the the law of Conservation of Energy, there is no loss in energy

So, the room just gets hotter.