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Units of Measurement
Area
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Did you know that
the hunting area of a pack of wolves is 1 000 m2?
the surface area of a dragonfly's wings is 1 380 mm2?
the largest leaves are found on the Abcasia maerorrhiza plant of East Malaysia; each leaf has a surface area of 317 m2? |
The abbreviations used by scientists for the units of area are as follows:
Abbreviation |
Area |
km2 |
square kilometre |
ha |
hectare |
m2 |
square metre |
cm2 |
square centimetre |
mm2 |
square millimetre |
The relationship between these units of area is:
Unit of Area |
Relationship |
1 km2 = 1 000 000 m2
1 ha = 10 000 m2
1 m2 = 10 000 cm2
1 cm2 = 100 mm2 |
Length
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Did you know that
a blue whale is 33,6 m long?
a giant squid is 17 m long?
the eucalyptus plant can reach 132 m in height?
the tallest man is 2,72 m in height?
the deepest roots reach 120 m into the soil? |
The abbreviations used by scientists for the units of length are as follows:
Abbreviation |
Length |
km |
kilometre |
m |
metre |
cm |
centimetre |
mm |
millimetre |
µm |
micrometre |
The relationship between these units of length is:
Unit of Length |
Relationship |
1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm
1mm = 1000 µm |
Load
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The load is the amount of mass carried by a certain unit of area. For example, the load on an insect's wings is measured as the body mass of the insect divided by the surface area of its wings.
body mass : wing surface area = load in mg/mm2 |
Mass
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The most massive living organism on Earth is a plant. It is called the giant sequoia which can have a mass of 2500 tonnes, including its roots?
A housefly has a mass of 12mg?
The dolphin has a mass of around 40kg? |
Abbreviation |
Units of Mass |
tonnes |
tonnes |
kg |
kilogramme |
g |
gramme |
mg |
milligramme |
Speed
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Speed measures the movement of something in a certain time interval. For example, we can measure the speed of the movement of an animal in
metres per hour = m/h
or kilometres per hour = km/h |
For other measurements, such as the rate of your heartbeat, we would use the measurement
beats per minute = beats/min |
Or, for the movement of an insect's wings, we would study the
beats per second = beats/s |
The cheetah has a maximum speed of 115 km/h.
The snail slithers along at a maximum speed of 0,83 m/min.
The tuna swims at a maximum speed of 80 km/h.
The sap in a tree moves at a speed of 100cm/h. |
Time
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The abbreviations for the units of time are:
Abbreviation |
Units of Time |
h |
hour |
min |
minute |
s |
seconds |
Remember that:
60 minutes = 1 hour
60 seconds = 1 minute
so 1 min 30 s = 1,5 min (not 1,30 min) |
Volume
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Did you know that
an elephant needs to drink between between 70dm3 and 90dm3 of water each day?
a man with a mass of 70kg has 5,645dm3 of blood in his body?
the human lungs can hold a maximum of 6dm3 of air? |
Abbreviation |
Area |
m3 |
cubic metre |
dm3 |
cubic decimetre |
cm3 |
cubic centimetre |
mm3 |
cubic millimetre |
The relationship between these units of area is:
...
Unit of Volume |
Relationship |
1 cm3 = 1 000 m3
1 dm3 = 1 000 cm3
(note that 1 dm3 used to be called 1 litre) |
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©
Paul Billiet and Shirley Burchill 2008 |
The Open Door Web Site