"Characteristics of Sound" Sound Phenomenon PPT Courseware 7

Description

"Characteristics of Sound" Sound Phenomenon PPT Courseware 7

Knowledge point one: Tone

1. In physics, the high and low sounds are called pitches.

2. The pitch is related to the speed of the sound-emitting body's vibration. The faster the object vibrates, the higher the pitch.

3. Frequency: The number of times an object vibrates per second, used to describe the speed of the object's vibration; the unit is Hertz, referred to as Hertz, which corresponds to Hz.

For example: if an object vibrates 400 times in 2 seconds, the frequency is 200Hz.

4. The relationship between pitch and frequency: Frequency determines the pitch of the sound. The greater the frequency, the higher the pitch; the smaller the frequency, the lower the pitch.

5. From the sound waveform diagram, the denser the waveform, the higher the frequency of the sound, and the higher the pitch of the sound.

As shown in the figure on the right, two different tuning forks A and B have different frequencies. In the same time t0, A vibrates 3 times with a small frequency and a low pitch; B vibrates 9 times with a high frequency and a high pitch.

Knowledge Point 2: Sounds that are inaudible to the human ear—ultrasound and infrasound waves

1. The frequency of sound that people can feel has a certain range. The frequency range of sound that most people can hear is from 20Hz to 20000Hz. Usually we call the sound in this frequency range sound.

2. People call sounds with frequencies higher than 20,000 Hz ultrasonic waves because they have exceeded the upper limit of human hearing.

3. Sounds with frequencies below 20Hz are called infrasound waves because they are below the lower limit of human hearing.

4. The sounds that humans can hear, sound, ultrasonic waves, and infrasound waves are collectively called sounds.

practise:

1. Sound is produced by the vibration of objects, but we see the butterfly wings vibrating, but we cannot hear the sound caused by the vibration of the wings. This is because the frequency of butterfly wings vibrating is ______20Hz (optional "less than" or "above"). This kind of inaudible sound wave is very destructive. During the "5 • 12" Wenchuan earthquake, many citizens in Guiyang, more than 600 kilometers away, suffered from dizziness, nausea and other symptoms, which were related to this sound wave. We call this sound wave __sound wave.

2. As shown in the picture, according to the information given in the picture, which of the following statements is correct? [ ]

A. Bats can emit sounds with a frequency of 400Hz

B. Humans can hear all frequencies of sounds emitted by bats

C. The frequency range of human hearing is larger than the frequency range of human vocalizations.

D. 15Hz sound can be heard by human ears as long as the amplitude is large enough.

Knowledge point three: tone and color

1. Timbre: Also called timbre, it reflects the quality and characteristics of the sound. Everyone's voice has its own characteristics, and the sound produced by each instrument also has its own characteristics. This characteristic is called timbre.

2. Determinants of timbre: Timbre is determined by factors such as the material, shape, and structure of the sound emitter.

【Notice】

1. Timbre is a characteristic of the sound emitter itself. It is an important basis for us to distinguish different sound emitters. If the sound emitter changes, the timbre will also change. For example, experienced melon growers can tell whether the watermelon is ripe by tapping it lightly.

2. The timbre of the same person will also change with age and factors such as diet, daily life, health, and training. Singers wake up early every day to "stretch their voices" in order to maintain their beautiful timbre.

3. Sounds emitted by different sound emitters with the same pitch and loudness but different timbres generally have different waveforms. As shown below:

practise:

1. Xiaojun is a music lover. He can distinguish the sounds of various musical instruments from the ensemble of musical instruments in the concert. When he distinguished the sounds produced by various musical instruments, he based them on the [ ]

A. Loudness B. Pitch C. Timbre D. Rhythm

2. When answering the phone, it is easy to distinguish the voice of an acquaintance, which is mainly judged based on the sound of the sound; when listening to music in a noisy public place with headphones, you often need to increase the volume, which increases the sound. ＿＿＿, if things continue like this, it will lead to hearing loss. (Optional "Tone", "Loudness", "Tone Color")

3. At the concert, Xiao Chen, who was sitting in the back row, could clearly hear the singing of his favorite star. Because the singer's voice is greatly enhanced by the amplification equipment. Although the singer on the stage cannot be seen clearly, he can still identify the singer based on the sound of his voice.

4. Several students in the music group made their own instruments. The waveforms emitted by the instruments are as shown in the figure. The incorrect statement is [ ]

A. Musical instruments vibrate when they sound.

B. The timbre of the musical instruments is the same

C. The loudness of the sound produced by the musical instruments is the same.

D. The musical instruments sound in the same tone

Keywords: Acoustic phenomenon teaching courseware, Sound characteristics teaching courseware, People's Education Edition eighth grade physics PPT courseware download, eighth grade physics slide courseware download, Acoustic phenomenon PPT courseware download, Sound characteristics PPT courseware download, .PPT format;

For more information about the "Acoustic Phenomenon Characteristics of Sound" PPT courseware, please click the "Acoustic Phenomenon ppt Characteristics of Sound ppt" tag.

"Characteristics of Sound" Sound Phenomenon PPT Courseware 11:

"Characteristics of Sound" Acoustic Phenomenon PPT Courseware 11 Learning Objectives 1. I want to know what pitch and loudness are and be able to distinguish between them. Through exploration, I can understand the relationship between pitch and frequency, and the relationship between loudness and vibration radiation. I will initially use the control variable method to design experiments.

"Characteristics of Sound" Sound Phenomenon PPT Courseware 10:

"Characteristics of Sound" Acoustic Phenomenon PPT Courseware 10 Teaching Objectives 1. Understand the characteristics of sound 2. Know that pitch is related to the frequency of the sound emitter, and loudness is related to the amplitude of the sound emitter 3. Pay attention to the rigor of scientific terminology 4. Different sound emitters emit The timbre of the music is different from the same pitch...

"Characteristics of Sound" Sound Phenomenon PPT Courseware 9:

"Characteristics of Sound" Acoustic Phenomenon PPT Courseware 9 Learning Objectives 1. Understand the characteristics of sound; 2. Know that the pitch of sound is related to the frequency of the sound emitter; 3. Know that the loudness of sound is related to the amplitude of the sound emitter; 4. Know the different sounds The timbre of the sound produced by the body is different. Know...

File Info

Update Time: 2024-06-27

This template belongs to Physics courseware People's Education Edition Physics for Grade 8, Volume 1 industry PPT template

Preview