Water, Air, and Energy


Facts about Water and Energy

Water accounts for 60% of our total weight
Density = 1 g/ml
Water disposal
            Respiration = 0.5 liter per day
            Sweating and transpiration = 0.9 liter per day, more in hot weather
            Urine = 1.5 liter per day
            Feces = 0.1 liter per day

Water consumption
            Drinking water = 1.5 liter per day
            Water in food = 0.9 liter per day
            Water produced during the metabolism of food = 0.6 liter per day

Water use
            Saliva = l liter per day
            Gastric juice = 2 to 2.5 liter per day
            Bile = 0.5 liter per day
            Pancreatic juice = 0.7 liter per day
            Intestinal secretion = 3 liter per day
            Blood contains 3 to 4 liter of water
Global water     
            Ocean covers 70% of Earth's surface
Solar power
            Average power available from sunlight on Earth (day and night) = 300 Watts per m2
            (0.3 kilowatts per square meter) = 300 Joules/second m2
            Earth's surface area = 5.1 x 108 km2 (square kilometers)

Useful conversions:

1 kg = 2.2 pounds
Watt = Joules per second; W = J/sec
1 ( km)2 = (103 m)2 = 106 m2