Question
Tania is investigating how molecular motion relates to convection. She made a solar updraft tower by taping together three empty tin cans with the tops and bottoms removed. Then, she attached a paper fan to the top of the tower with wire, tape, and a thumbtack so that the fan would spin freely when air passed. Finally, she stacked the tower on top of two books so that air could freely pass through the tower. When the solar tower is exposed to sunlight, the metal cans absorb heat and transfer it to the air inside of the tower.
The tower is shown below. During Tania’s experiment, she placed the tower in the path of direct sunlight. She recorded the temperature of the tower and the number of times the fan on top of the tower spun. Which of the following correctly explains the process that made the fan spin?
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1 point
Captionless Image
As the air inside of the tower became hot, the molecules of air became less dense. This caused the hot air to rise and push past the fan, causing the fan to spin.
As the air inside of the tower became hot, the molecules of air became more dense. This caused the hot air to sink and pull in cool air from the top of the tower, causing the fan to spin.
As the metal cans heated, the molecules of hot and cold air inside of the tower separated. This made the hot and cold air inside of the tower swirl, causing the fan to spin.
As the metal cans heated, the molecules of hot and cold air inside of the tower separated. This made the hot air sink and the cold air rise, causing the fan to spin.
The tower is shown below. During Tania’s experiment, she placed the tower in the path of direct sunlight. She recorded the temperature of the tower and the number of times the fan on top of the tower spun. Which of the following correctly explains the process that made the fan spin?
*
1 point
Captionless Image
As the air inside of the tower became hot, the molecules of air became less dense. This caused the hot air to rise and push past the fan, causing the fan to spin.
As the air inside of the tower became hot, the molecules of air became more dense. This caused the hot air to sink and pull in cool air from the top of the tower, causing the fan to spin.
As the metal cans heated, the molecules of hot and cold air inside of the tower separated. This made the hot and cold air inside of the tower swirl, causing the fan to spin.
As the metal cans heated, the molecules of hot and cold air inside of the tower separated. This made the hot air sink and the cold air rise, causing the fan to spin.
Answers
GPT-4o mini
The correct explanation for the process that made the fan spin is:
**"As the air inside of the tower became hot, the molecules of air became less dense. This caused the hot air to rise and push past the fan, causing the fan to spin."**
This statement accurately describes the principle of convection: when air is heated, it becomes less dense and rises, creating movement in the air that can cause a fan to spin.
**"As the air inside of the tower became hot, the molecules of air became less dense. This caused the hot air to rise and push past the fan, causing the fan to spin."**
This statement accurately describes the principle of convection: when air is heated, it becomes less dense and rises, creating movement in the air that can cause a fan to spin.