1. Length
1.1. S.I unit: metre(m)
1.2. Definition of meter
1.2.1. the length of the path travelled by light in a vauum during a time interval of 1/299892458 of a second.
1.3. Instruments to measure length
1.3.1. Metre Rule
1.3.1.1. Precision: 1mm
1.3.1.2. Precautions: To prevent parallax error, the eye should be placed vertically above the mark being read
1.3.2. Vernier Calipers
1.3.2.1. Precision: 0.1mm
1.3.2.2. 3parts
1.3.2.2.1. Inside jaws
1.3.2.2.2. Outside jaws
1.3.2.2.3. Tail
1.3.3. Micrometer Screw Gauge
1.3.3.1. Precision: 0.01mm
2. Prefixes in Units
2.1. Why use prefixes?
2.1.1. Some numerical values are either too large or small and involve several decimal places
2.2. tera
2.2.1. T
2.2.1.1. 10 to the power of 12
2.3. giga
2.3.1. G
2.3.1.1. 10 to the power of 9
2.4. mega
2.4.1. M
2.4.1.1. 10 to the power of 6
2.5. kilo
2.5.1. k
2.5.1.1. 10 to the power of 3
2.6. hecto
2.6.1. h
2.6.1.1. 10 to the power of 2
2.7. deka
2.7.1. da
2.7.1.1. 10 to the power of 1
2.8. deci
2.8.1. d
2.8.1.1. 10 to the power of -1
2.9. centi
2.9.1. c
2.9.1.1. 10 to the power of -2
2.10. milli
2.10.1. m
2.10.1.1. 10 to the power of -3
2.11. micro
2.11.1. μ
2.11.1.1. 10 to the power of -6
2.12. nano
2.12.1. n
2.12.1.1. 10 to the power of -9
2.13. pico
2.13.1. p
2.13.1.1. 10 to the power of -12
2.14. femto
2.14.1. f
2.14.1.1. 10 to the power of -15
3. Luminous Intensity
3.1. S.I unit: candela (Cd))
4. Amount of substance
4.1. S.I unit: mole (mol)
5. Electric Current
5.1. S.I. unit: ampere(A)
6. Time
6.1. S.I. unit: second(s)
6.1.1. Definition of second: 9192631700 times the period of oscillation of radiation from the cesium atom.
6.2. Instruments to measure time
6.2.1. Digital Stopwatch
6.2.1.1. Precision: 0.01s
6.2.1.2. Precautions: To prevent human reaction error when taking timings, take the average of three timings.
7. Mass
7.1. S.I.unit: kilogram(kg)
7.1.1. Definition of kilogram: the mass of a certain cylindrical piece of platinum-iridium alloy kept at the International Bureau of Weights and Measure at Sevres, France
7.2. Definition
7.2.1. The quantity of matter it contains
7.3. Instruments to measure mass
7.3.1. Electronic beam balance
7.3.1.1. Precision: 0.1g