Units and Constants
zUnits:
yPower
in watts (joules/second)
yEnergy
(power x time) in watt-hours
zConstants:
y1 m =
0.3048 ft exactly by definition
y1
mile = 1.609 km; 1m/s = 2.204 mi/h (mph)
y1
mile2 = 27878400 ft2 = 2589988.11 m2
y1 ft2 = 0.09290304 m2; 1 m2 = 10.76391042 ft2
y1 ft3 = 28.32 L = 7.34
gallon = 0.02832 m3; 1 m3 = 264.17 US
gallons
y1 m3/s = 15850.32 US gallons/minute
yg =
32.2 ft/s2 = 9.81 m/s2; 1 kg = 2.2 pounds
yAir
density, ρ (rho), is 1.225 kg/m3 or 0.0158 pounds/ft3 at 20ºC at sea level
ySolar
Constant: 1368 W/m2 exoatmospheric or 342 W/m2 surface (80 to
240 W/m2)
y1 HP
= 550 ft-lbs/s = 42.42 BTU/min = = 746 W (J/s)
y1 BTU
= 252 cal = 0.293 Wh = 1.055 kJ
y1
atmosphere = 14.696 psi = 33.9 ft water = 101.325 kPa = 76 cm Hg =1013.25 mbar
y1 boe
(42- gallon barrel of oil equivalent) = 1700 kWh
9.3 020402