Key Words: cold air, high density
Answer: Cold air that is produced from the air con has a higher density compared to surrounding air. This causes the cold air to sink. The warm air near the bottom of the room will rise as it has a lower density. This allows a convection current to be set up to cool the room.
If the air con is placed at the bottom of the room, the cold air will remain at the bottom of the room. This will prevent the whole room from being cooled.
Tip: A common misconception among students is that cold air just sinks. But, most students do not understand why cold air sinks. This is because the density of cold air is higher than the surrounding air.
Experiment #7 - Forces (Frictional Force)
Experiment #6 - Forces (Frictional Force)
Experiment #5 - Forces (Interactions)