Answer the following question:
A student takes four objects: a steel spoon, a wooden ruler, a plastic bottle, and a metal coin. He gently strikes each object with the same force and listens to the sound produced. He observes that the steel spoon and metal coin produce a clear ringing sound, while the wooden ruler and plastic bottle produce a dull sound.
1. Which objects were found to be sonorous?
2. Which conclusion can be drawn from the activity?
3. Which situation best demonstrates the practical use of sonority?