Nia's Light-Path Notes
At an autumn farm stand, Nia and her class tested a small red basket before the stand opened. The basket did not make its own light. A lantern was placed on one side of the basket, and an observer looked through an opening on the other side. The class used an opaque card, which blocks light, and a clear sheet, which lets light pass through. They kept the basket, lantern, and observer in the same places unless a test record says otherwise.
In Test A, the lantern was on, the two openings were clear, and the observer saw the basket. In Test B, the lantern was off, and the observer did not see the basket. In Test C, the lantern was on, but an opaque card was placed between the lantern and the basket. The observer did not see the basket.
In Test D, the lantern was on and the card was moved to a place between the basket and the observer. The observer did not see the basket. In Test E, the card was replaced with a clear sheet at that same place. The observer saw the basket. In Test F, the lantern was on and the observer saw a white cloth in place of the basket.
Nia wrote that the class could observe whether the basket was visible, but the path of light inside the setup was a model. Nia asked the class to draw a model that connects the lantern, the basket, and the observer's eye.