Metric System
Length
(L)
Mass
(M)
Weight
(W)
Volume
(V)
Density Temperature
(T)
(D)
1cm
1cm
Meter Stick
Balance
Spring Scale
1cm
Graduated
Cylinder
Sand
Mass/Volume
Thermometer
The Metric System
---The Universal Language of Measurement---
• Metric System – scientists & engineers
use this language to communicate
• The metric system is often referred to as the
International System of Units (abbreviated
“SI”)
• The metric system is based on the number 10
and multiples of 10.
Length
The distance between two points
• Meter – the basic unit of length in the metric system
1 meter = 1 m
• Centimeter – one hundredth of a meter
1 cm = 1/100 m = 0.01 m
100 cm = 1 m
• Millimeter – one thousandth of a meter
1 mm = 1/1000 m = 0.001 m = 1/10 cm = 0.1 cm
1000 mm = 1m
• Kilometer – one thousand meters
1 km = 1000m
1 m = 1/1000 km
• Light year –the distance light travels in one year
Speed of light = 300,000 km/s
Volume
The amount of space an object takes up
• Liter – is the basic unit of volume in the metric system
1 Liter = 1 L
• Milliliter – is one thousandth of a Liter
1 mL = 1/1000 L = 0.001 L
• Milliliters and Liters are used to measure the volume of
• Cubic centimeters – is the metric unit used to measure
the volume of
• A cubic centimeter is equal to the volume of a cube that
measures 1 cm by 1 cm by 1 cm (cm3).
A volume of a cubic centimeter (cm3) is exactly equal to the
volume of one milliliter.
1cm
1cm
1cm
= 1 cm3 = 1 mL
Mass
a measure of the amount of matter in an object
• Kilogram – the basic unit of mass in the
metric system
1 kg = 1000 grams
• Gram – one thousandth of a kilogram
1 g = 1/1000 kg = 0.001 kg
1000 g = 1 kg
• Milligram – one thousandth of a gram
1 mg = 1/1000 g = 0.001 g
1000 mg = 1 g
Weight
a measure of the attraction between two objects due to gravity
• Gravity - a force of attraction between two
masses.
• The strength of the gravitational force between
two objects depends on the masses of the
objects and the distance between them:
a) The greater the mass, the greater the gravitational
force.
b) The greater the distance between the two objects,
the weaker the gravitational force between them
• Newton (N) - the basic unit of weight in the
metric system.
Mass vs. Weight
• An object has a universal mass, but may have
different weight depending on gravity.
• The mass of an object does not change.
• The weight of an object changes as a result of
changes in gravity.
• A pineapple on earth weighs more than on the
moon because the earth’s gravity is greater. But
the pineapple’s mass always remains the same
wherever you go (unless you get hungry and eat it!).
Density
a measure of the amount of matter that occupies a unit certain volume
• Density = mass/volume
(units are usually g/mL)
The density of water = 1.00 g/mL
This means that one gram of water occupies
one milliliter of volume.
The density of oil =
0.91 g/mL
If lighter fluids float on heavier fluids, do you
expect water to float on oil?
Sand grains
If the human body is nearly 70%
water, is it possible to float in
quicksand? Should you get
worried?
Temperature
a measure of how hot or cold something is
• Celsius = a unit of temperature in the
metric system
• Water freezes at 0° C.
• Water boils at 100° C.
• Normal body temperature is 37° C
• Room temperature is 21° C.
Temperature
(continued)
• Kelvin = another unit of temperature in the
metric system.
• The lowest possible temperature is
0 Kelvin (-273 ° C). This is Absolute Zero.
• To convert from Celsius to Kelvin:
K = C + 273°
Metric Prefixes
Prefix
Symbol
Meaning
kilo-
k
1000
thousand
hecto-
h
200
hundred
deka-
da
10
ten
deci-
d
0.1
tenth
centi-
c
0.01
hundredth
milli-
m
0.001
thousandth