1. Generation of sound (1) Tuning fork experiment method: Put a suspended table tennis ball in contact with a silent tuning fork, and the ball will not jump; knock the tuning fork, and then make the ball contact the tuning fork, and the ball will jump. Conclusion: The object making the sound is vibrating. (2) Steel ruler experiment method: Use a long steel ruler, press it tightly on the edge of the tabletop, adjust the length of the steel ruler extending out of the tabletop, and move the end of the steel ruler that extends out of the tabletop. The steel ruler can make a sound. Observe that the steel ruler The ruler is vibrating. Conclusion: The object making the sound is vibrating. 2. Propagation of sound (1) Solid sound transmission experiment method: Use a desk to conduct the experiment. Two students are in a group. A puts one ear on the desk and blocks the other ear. B taps the bottom or leg of A's table without A seeing the action. A can hear B knocking on the table. Conclusion: Solids can transmit sound. (2) Liquid sound transmission experiment method: Place sound-producing objects (such as music cards, mobile phones, alarm clocks, etc.) in a sealed plastic bag. After the plastic bag is immersed in water, the sound emitted by the sound-emitting body can still be heard. . Conclusion: Liquids can transmit sound. (3) Gas sound transmission experiment method: The teacher speaks and the students can hear it while sitting in their seats. Conclusion: Air can carry sound. (4) Vacuum ringing experiment method: Place the ringing alarm clock in a glass cover where the air is gradually extracted, and the ringing sound heard by people gradually weakens. Conclusion: Sound cannot travel through a vacuum. 3. Sound tone method: Use a long steel ruler and press it against the edge of the tabletop so that the length of the steel ruler extending out of the tabletop is about 1/3 of the total length. Move it to extend out of the end of the tabletop and listen to the steel ruler. Listen to the sound the ruler makes and observe how fast it vibrates. Then shorten the length of the steel ruler extending out of the table, and move the end of the ruler to make it vibrate at roughly the same amplitude as last time. Listen to the changes in the sound it makes compared to last time. It was found that the faster the steel ruler vibrates and the higher the frequency, the higher the pitch of the sound it makes. Conclusion: Pitch is related to frequency. The greater the frequency, the higher the pitch. 4. Sound loudness method: Use a long steel ruler, press it tightly on the edge of the table, adjust the length of the steel ruler extending out of the table appropriately, keep the extension length unchanged, and use different sizes of force to move it out of the table. The end of the steel ruler allows the steel ruler to make sound and observe the amplitude of the steel ruler's vibration. Listen to the size of the sound and find that when the force is greater, the amplitude of the steel ruler is larger and the sound is louder.

Conclusion: The loudness of sound is related to the amplitude. The greater the amplitude, the greater the loudness.