Page 345 - Industrial Power Engineering and Applications Handbook

N324 Industrial Power Engineering and Applications Handbook
Important formulae Absolute zero is the theoretical temperature, at which
the atoms and molecules of a substance have the least
Moment of inertia possible energy. This possibly is the lowest attainable
GD2 = 4. g. (m?) temperature.
= 4 wr2 Conversion table
where Lengths
W = m . g (mass x gravity) 1 inch = 25.4 mm
r = radius of gyration 1 foot = 30.48 cm
1 mile = 1.609 km
Temperature 1 cm = 0.3937 inch
Conversion from Fahrenheit (OF) to Celsius ("C) 1 metre = 39.37 inches
= 3.28 feet
F-32 C
-- - (A.6) 1 km = 3280 feet
9 5 = 0.621 mile
where
F = "F Areas
c = "C
1 in2 = 6.45 16 cm2
Absolute zero = kelvin (1 K) 1 ft2 = 0.0929 y2
1 K = -273.15"C 1 cm2 = 0.155 in-
1 m2 = 10.8 ft2
1 m2 = 1.196 yd2
Table A.6 Some useful units
Volumes/weights
~ ~ ~ ~
Unit oj" *I Imperial gallon (UK) = 4.546 litres
~ ~~ ~~~ ~~
1 N = 0 101972 kgt Force *1 US gallon = 3.79 litres
1 pint = 0.568 litre
1 kg f = 9 807 N Force 1 litre = 0.22 Imperial gallons
1 Ib = 0.453 kg
~~~~~~
1 kg tm = 9 807 N m Energyltorque 1 kg = 2.204 Ib
1 MT = 0.984 ton
~~~ ~~~~
1 kg f/m2 = 9 807 N/m2 Force
~ ~ ~ ~ ~ _ _ _ 1 T = 1.016 MT _ _
_
lJ=1Nm=OI0187kg fm Energyhorque 1 litre per second = 13.2 gallons per minute
1 ft' of water = 6.23 gallons
1 W = 1 Us Power 1 rn3 of water =220 gallons = 35.31 ft3
1 ft3/s = 22,500 gallons/h(GPH)
1 Wb=lV.s Flux = 375 gallons/minute (GPM)
1 atmosphere = 30" of mercury
1 T = 1 Wb/m2 Flux density = 14.7 lb/inz
1 Hz = 1 Hz (s-I) Frequency Torqu egorce
1 Pa (Pascal) = 1 N/m2 Pressure 1 cm.kg = 0.866 inch pounds
~~~ 1 m.kg = 7.23 foot pounds
1 bar= IO5 N/m' 1
= 1 atm. Pressure Work done
= 101325 x 105N/m2 1 Preqrure = 1.341 h.p.
1 dtm (atmoqphere) = I kgf/cm2 1 kW = 1.36 metric h.p. (PS)
= 735 6 mm of mercury
1 bar =lo5 pascal = 0 9870 atm 1 h.p. = 0.746 kW
= 1.014 PS (metric h.p.)
~~~~~~ 1 PS (mhp) = 0.736 kW
I01325 x 10' N/m' = 0.986 h.p.
1 torr =
760 1 Preswre
- 1 "Unless specified all conversions made earlier relate to Imperial
- 760 atm
gallons only.