"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 7

Description

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 7

review review

1. What are the uses of sound?

(1) Sound waves can transmit information

(2) Sound waves can transfer energy

What adverse effects does sound have on our daily lives?

1. What kind of sound is noise?

2. What harm does noise do to people?

3. How to control noise?

1. Definition of noise:

(Note: Due to different angles, the meaning of the referred noise is also different)

1. Noise from a physical perspective: it is the sound emitted when the sound-emitting body vibrates irregularly.

What is the difference between the waveforms of noise and music?

Musical sound: The sound produced when the sound-emitting body vibrates regularly.

Noise: The sound produced when the sound-emitting body vibrates irregularly.

2. Noise from the perspective of environmental protection:

All sounds that hinder people's work and study, affect people's lives, and interfere with people's hearing are noises.

Please tell me: What are the sources of noise around you?

2. Noise intensity level

1. Classification of noise levels: expressed by decibel (dB) value; it essentially refers to the loudness.

Does 0dB mean there is no sound?

0 dB: The weakest sound a person can hear just now - the lower limit of hearing

20dB: the sound of whispering

30~40dB: ideal quiet environment

In order to ensure rest and sleep, the noise should be controlled not to exceed 50dB.

In order to ensure work and study, the noise should be controlled not to exceed 70dB;

In order to protect hearing, noise should be controlled not to exceed 90dB;

Dangers of noise:

Psychological effects: It makes people irritable, lacks concentration, hinders sleep and rest, and affects work efficiency.

Physiological effects: headache, indigestion, blurred vision, deafness, etc., or even confusion, shock or death in severe cases.

Physical effects: High-intensity noise can damage buildings.

3. Control noise

1. Prevent noise generation - control at the sound source

2. Block the propagation of noise ----- control during the propagation process

3. Prevent noise from entering human ears----control at human ears:

Apply what you learn

1. In physics, the sound produced when the sound-emitting body is called __________ is called noise. From the perspective of environmental protection, all __________ sounds are noise.

2. People use ________ to classify sound levels. In order to protect hearing, the sound should not exceed ________ decibels; in order to ensure work and study, the sound should not exceed ________ decibels; in order to ensure rest and sleep, the sound should not exceed _______ _decibel

3. Which of the following statements about noise is wrong ( )

A. The pleasant music may be noise;

B. Noise is emitted when the machine vibrates during operation;

C. Noise harms people’s physical and mental health;

D. Sounds that interfere with the sounds people want to hear are noises.

4. Which of the following sounds is noise is___________.

a. The sound of reading aloud during morning reading

b. The sound of running car engines in the city

c. Noise during self-study classes

d. The sound of gongs and drums during the Peking Opera performance in the theater

e. The sound of electric drills when renovating a house

f.The sound of fireworks at night during the Lantern Festival

Keywords: Acoustic phenomenon teaching courseware, Noise hazards and control teaching courseware, Shandong Education Edition eighth grade physics PPT courseware download, Eighth grade physics slide courseware download, Acoustic phenomenon PPT courseware download, Noise hazards and control PPT courseware download, .PPT format;

For more information about the "Hazards and Control of Acoustic Phenomenon Noise" PPT courseware, please click the "Hazards and Control of Acoustic Phenomenon Noise ppt" ppt tag.

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 10:

"The Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 10 Introducing a new lesson The high-spirited march is exciting, and the melodious singing is mesmerizing. The March of the Chinese People's Liberation Army, violin playing, the harsh sound of car horns and the roar of machines on the construction site make people...

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 9:

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 9 1. Noise and its sources Read the text and discuss: 1. From a physical point of view, what is noise? �2�What is noise from the perspective of environmental protection? Why is music sometimes also noise? �3�..

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 8:

"Hazards and Control of Noise" Acoustic Phenomenon PPT Courseware 8 Experience 1 Feel the music and noise Activity 1: (1) Listen to a piece of beautiful music; (2) Scratch the glass with a nail and listen to the sound produced. Activity 2: (1) Everyone sings a song together; (2) Everyone is studying on their own, and...

File Info

Update Time: 2024-10-04

This template belongs to Physics courseware Lu Jiao edition eighth grade physics volume 1 industry PPT template

Preview