1 / 24

Chapter 1 Measurement 第 1 章 測量

Chapter 1 Measurement 第 1 章 測量. Chapter 1 Measurement. 1-1 What is Physics? 1-2 Measuring Things 1-3 The International System of Units 1-4 Changing Units 1-5 Length 1-6 Time 1-7 Mass. 1-1 What is Physics?. Science and engineering are based on measurements and comparisons .

janetwilliams
Download Presentation

Chapter 1 Measurement 第 1 章 測量

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 1 Measurement第1章 測量

  2. Chapter 1 Measurement 1-1 What is Physics? 1-2 Measuring Things 1-3 The International System of Units 1-4 Changing Units 1-5 Length 1-6 Time 1-7 Mass

  3. 1-1 What is Physics? • Science and engineering are based on measurements and comparisons. • Global Positioning System (GPS) 全球定位系統

  4. 1-2 Measuring Things • We measure each physical quantity in its own units, by comparison with a standard. • Base standards must be both accessible and invariable.

  5. 1-2 Measuring Things • standard 標準 • unit 單位 • base quantity 基本量 • derived quantity 導出量 • base unit 基本單位 • derived unit 導出單位

  6. SI Base Quantities • length 長度 • mass 質量 • time 時間 • electric current 電流 • thermodynamic temperature 熱力學溫度 • amount of substance 物質量 • luminous intensity 發光強度

  7. 1-3 The International System of Units • International System of Units 國際單位制 • SI (Système International) 國際單位制 • metric system 公制 • scientific notation 科學記號、科學記法 • 3.56  109 m • 4.92  107 s

  8. 10進位倍數和分數符號

  9. 1-4 Changing Units • conversion factor 換算因子、換算因數 • significant figure 有效數字 • decimal place 小數位、小數位數

  10. 1-5 Length • In 1792, Republic of France established a new system of weights and measures. • The unit of length, the meter, was defined as one ten-millionth of the distance from the north pole to the equator. • International Bureau of Weights and Measures 國際度量衡局 • Standard meter bar • Platinum-Iridium bar

  11. 1-5 Length • In 1960, the meter was defined to be 1650763.73 wavelengths of a particular orange-red light emitted by krypton-86 in a gas discharge tube. • Krypton 氪 • Gas discharge tube 氣體放電管

  12. 1-5 Length • In 1983, the meter was defined as the length of the path traveled by light in a vacuum during a time interval of 1/299 792 458 of a second. • The speed of light c is then exactly c = 299792458 m/s.

  13. Standard 標準 • Base standards must be both accessible and invariable. • primary standard 原級標準、原標準 • secondary standard 次級標準、副標準 • order of magnitude 數量級

  14. 1-6 Time • Time has two aspects • When did it happen? • What is its duration? • Earth’s rotation • Quartz clock 石英鐘 • One second is the time taken by 91992631770 oscillations of the light emitted by a cesium-133 atom. • Atomic clock 原子鐘 • National Institute of Standards and Technology (NIST) 國家標準與技術研究院

  15. 10-hour watch

  16. Variations in the length of the day over a 4-year period

  17. 1-7 Mass • Carbon-12 atom • atomic mass unit, u原子質量單位 1 u = 1.66053886  1027 kg • Density, 密度 • liquefaction 液化 • quicksand 流沙

  18. The international 1 kg standard of mass (platinum-iridium)

  19. Uncertainty 誤差 • Accuracy 準確度 • Accuracy refers to how close a measurement is to the true value. • Precision 精密度、精確度 • Precision in a strict sense refers to the repeatability of the measurement using a given instrument.

More Related