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vâng cảm ơn

In daily life, music plays an important role in improving human’s spirit. Music is a wide topic and heated issue that connect people when talking about it. As people have deep knowledge about all kind of music, they can be able to lengthen a conversation. Music is created by both melody and rhythm in order to make a complete song. There are several styles of music such as: pop, hip-hop, ballad, country and so on. Its tune and meaning also differ from country to country. I love music for many reasons. First, it helps people relax and reduces stress from studying and working environment. For example, when having problems in life, one should listen to favorite music and them make up one’s mind. Second, music helps people in all aspects of life like: movie, business, .… There are an increasing number of famous singer and writer that distribute their money to establish charity fund for the poor. It saves many people’s lives and even improves to create a better living standard. Third, music is not simply rhythm it’s an art. Since music expresses feeling and emotion, it is a tool to heal one’s soul. A good example is that when you are in good mood, you listen to energy rock music; however when you don’t feel like doing anything, you need some relax music as country or romantic country. Human cannot lead a happy life without music cause music is a part of life, it appears on several environments. Nowadays, there are more and more intellectual-property pirates, which leads to suspicion on serious artists. Therefore, if an artist wants to become successful, they have to work on their own and totally commit to their work of art. Music is a diverse topic that many mysteries can be discovered from it; moreover, people have a right to protect and preserve this kind of art.

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còn thiếu

Tần số là số giao động trong 1 giây

2 phút= 120 giây vật thực hiện 1200 dao động 

1 giây ? dao động

số dao động trong 1 giây là:

1200/120= 10 (dao động)= 10Hz

Tìm số của vật là 10Hz. Vật có dao động nên âm phát ra âm tai người nghe đc âm có tần số từ 20Hz đến 20000Hz 

=>10Hz < 20Hz nên tai người ko nghe đc âm này phát ra