Physical quantities and units
作者：Nicholas Iphone
1. length
1.1. metre
1.1.1. the length of the path travelled by light in a vacuum during a time interval of 1/299792458 of a second
1.1.2. metre rule
1.1.2.1. measures max distance of 1.000m
1.1.2.2. measure up to accuracy of 1mm or 0.001m
1.1.2.3. place eye vertically over ruler to avoid parallax error
1.2. vernier caliper
1.2.1. measure up to an accuracy of 0.1mm
1.3. micrometer
1.3.1. measure up to an accuracy of 0.01mm
2. mass
2.1. quantity of matter a body contains
2.1.1. electronic balance
3. time
3.1. digital stopwatch
3.1.1. accuracy of 0.01s
3.2. analog stopwatch
3.2.1. accuracy of 0.1s
4. quantites
4.1. length
4.1.1. metre
4.1.1.1. m
4.2. mass
4.2.1. kilogram
4.2.1.1. kg
4.3. time
4.3.1. second
4.3.1.1. s
4.4. electric current
4.4.1. ampere
4.4.1.1. A
4.5. temperature
4.5.1. kelvin
4.5.1.1. K
4.6. amount of substance
4.6.1. mole
4.6.1.1. mol
4.7. luminous intensity
4.7.1. candela