Page 18 - Aeronautical Engineer Data Book

8 Aeronautical Engineer’s Data Book
4
28 kN rather than 2.8 2 10 N
1.25 mm rather than 0.00125 m
9.3 kPa rather than 9300 Pa

Table 2.2 SI unit prefixes

Multiplication factor Prefix Symbol
1 000 000 000 000 000 000 000 000 = 10 24 yotta Y
1 000 000 000 000 000 000 000 = 10 21 zetta Z
1 000 000 000 000 000 000 = 10 18 exa E
1 000 000 000 000 000 = 10 15 peta P
1 000 000 000 000 = 10 12 tera T
1 000 000 000 = 10 9 giga G
1 000 000 = 10 6 mega M
1 000 = 10 3 kilo k
100 = 10 2 hicto h
10 = 10 1 deka da
0.1 = 10 –1 deci d
0.01 = 10 –2 centi c
0.001 = 10 –3 milli m
0.000 001 = 10 –6 micro µ
0.000 000 001 = 10 –9 nano n
0.000 000 000 001 = 10 –12 pico p
0.000 000 000 000 001 = 10 –15 femto f
0.000 000 000 000 000 001 = 10 –18 atto a
0.000 000 000 000 000 000 001 = 10 –21 zepto z
0.000 000 000 000 000 000 000 001 = 10 –24 yocto y

2.3 Conversions
Units often need to be converted. The least con­
fusing way to do this is by expressing equality:
For example, to convert 600 lb thrust to
kilograms (kg)
Using 1 kg = 2.205 lb
Add denominators as
1kg 2.205 lb kg
3 = 33
x 600 lb
Solve for x
600 2 1
x = 3 = 272.1 kg
2.205
Hence 600 lb = 272.1 kg