Properties of Sound and Related Phenomena：練習問題

During a thunderstorm, we usually see a flash of lightning several seconds before we hear the thunder. What does this observation tell us about the speed of light and sound?

A student is investigating how the length of a vibrating string affects the sound it produces on a homemade instrument. If the student moves their finger to make the vibrating section of the string shorter while plucking it with the same force, how will the sound change?

Sound waves travel by passing vibrations from one particle to the next. Based on the arrangement of particles in different states of matter, in which of the following media would sound travel at the highest speed?

A ringing bell is placed inside a glass jar. If a pump is used to remove all the air from the jar to create a vacuum, what will happen to the sound we hear?

A student conducts an experiment with two identical rubber bands stretched over a wooden box. Rubber band X is stretched very tightly, while rubber band Y is stretched loosely. If both are plucked with the same strength, how will the sound of X differ from Y?

When studying Properties of Sound and Related Phenomena, a student uses a decibel meter to measure the environmental noise at a busy construction site. If the meter displays a high numerical value, what specific property of the sound is being measured, and what is its commonly used unit?

Sound travels at different speeds depending on the medium it passes through. Explain why sound travels fastest through solids compared to liquids or gases, and describe why a vacuum prevents sound from being heard even if a source is vibrating.

Explain why a sound becomes fainter as a listener moves further away from the source, and identify what happens to the amplitude of the sound waves during this process.

A student uses a drum to study how sound is produced and how its volume changes.

(a) Explain how the drum produces sound when it is hit with a drumstick. (1 point)

(b) If the student hits the drum harder, what happens to the intensity of the vibration and the loudness of the sound produced? (2 points)

Sound behaves differently depending on the materials and environment it encounters.

(a) When sound hits a hard and smooth surface, like a large tiled wall, what phenomenon usually occurs? (1 point)

(b) Why do movie theaters and recording studios often cover their walls with soft, porous foam or thick carpets? (2 points)

(c) A student blows across the top of two identical glass bottles. Bottle A is half-full of water, while Bottle B is nearly empty. Which bottle will produce a higher pitch sound? Explain your answer based on the vibrations of the air column. (3 points)