Methods: 1. Add a small amount of water to the glass and tap the glass with a pencil to make a sound;
2. put more water in the cup, tap the cup with the same force with a pencil to make a sound, and compare the tones of the two sounds.
Experiment 2. What determines the color of transparent objects?
Methods: The transparent cellophane with different colors was illuminated with a flashlight, and it was found that the color of the transparent object was the same as that of cellophane, indicating that the color of the transparent object was determined by the color of the transparent object.