Volume
volume explained | heart and river flow
Volume explained
Volume is measured in cubic metres (m3) or
variations on it using prefixes.
The litre
(L) is often used to measure volume. A litre is simply a special
name for a cubic decimetre. (A decimetre is 0.1 m, so a cubic decimetre is a cube 0.1 m, or 10 cm, on each side.)
1 L = 1 dm3
Hence 1 L ≡ 0.001 m3 (exactly). A cubic centimeter,
abbreviated as cc, is used to describe the size of car engines.
A cc is exactly the same thing as a mL.
1 mL = 1 cm3 = 1 cc
At room temperature at sea level one litre weighs 1 kg. So at
room temperature at sea level:
1 mL = 1 cm3 = 1 cc = 1 g
1 L = 1 dm3 = 1 kg
1,000 L = 1 m3 = 1,000 kg (1 tonne)
Note that the symbol for a litre is a capital L, although a lower
case very non-descript l or cursive ℓ is sometimes used. |
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Calculating volume
Volume of a cube:
length x width x height
Volume of a prism:
Work out which dimension the prism has been extruded through,
then:
area of face x length
Volume of a sphere:
4/3·π·r3
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Random facts – heart and river flow
The average adult has about 5 L of blood. The human heart pumps roughly 5 L/min, but the actual amount can vary from 4½ to 6½ L/min under ordinary conditions. The maximum cardiac output for normal people is in the range 14-20 L/min, but the heart of an Olympic athlete can pump up to 40 L/min.
The flow of the Amazon River accounts for 20% of the total flow of all the world's rivers, at about 6,600 km3 per year. That's roughly 12.5 billion L/min. That's the equivalent of the cardiac output of one third of the world's population.
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