College Physics (Algebra-Based) · 免费预览
物理量与单位
物理量取决于其测量或计算方式来定义，而每一次测量都以标准化的单位表示。SI 体系以基本单位（米、千克、秒、安培）为基础，并采用现代的原子定义，通过公制词头对这些单位加以扩展，再借助换算因子和量纲分析在各单位之间进行换算。
1. Physical Quantities and Units
Physical Quantities and Units
2. Fundamental and Derived Units
Fundamental and Derived Units
3. Fundamental SI units
Which of the following is a fundamental SI unit (not derived)?
4. Metric Prefixes and Orders of Magnitude
Metric Prefixes and Orders of Magnitude
5. The modern meter
How is the SI meter defined today?
6. Unit Conversion and Dimensional Analysis
Unit Conversion and Dimensional Analysis
7. Average speed in two unit systems
You drive 10.0 km from school to home in 20.0 min. Calculate your average speed (a) in km/h and (b) in m/s. Average speed is distance traveled divided by time of travel.
8. Reading a metric prefix
A microscope resolves detail down to about . Which prefix belongs on the unit for this length?
9. Same order of magnitude
Which pair of numbers has the same order of magnitude?
10. Setting up a conversion
To convert 80 m to km, which factor do you multiply by so the meters cancel?
11. The cesium second
The SI second is defined as the time for how many vibrations of a cesium-133 atom? Give the number.
12. Meters in a kilometer
How many meters are in 1 kilometer? Give the number.