metric system
DESCRIPTION
Metric System. Measurement. Measurements . The English system uses measurements like feet, yards, miles, and gallons . Also known as the International System of Units or the SI system. SI Units International System of Units Base Units. meter (m) gram (g) liter (L) Celsius (C) - PowerPoint PPT PresentationTRANSCRIPT
Metric SystemMeasurement
Measurements
•The English system uses measurements • like feet, yards, miles, and gallons.
•Also known as the International System of Units or the SI system
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•Length •Mass •Volume•Temperature •Time
meter (m)gram (g)liter (L)Celsius (C)seconds (s)
SI Units International System of Units
Base Units
Metric System•Common SI prefixes:•Kilo- (k) means 1,000•Hecto- (h) means 100•Deka- (da) means 10•Deci- (d) means 0.1 (one tenth)•Centi- (c) means 0.01 (one hundredth)•Milli- (m) means 0.001 (one thousandth)
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The metric system is a system of
measurement based on the number 10
Conversions between large and small quantities
K H D B d c m
King Henry Died By drinking chocolate milk
• This chart tells you three things:• How many places to move the decimal• In what direction to move the decimal• What base unit to use
K H D B d cm
Examples:4.51 kg = ________g
4587m = _________mm
1.23 mL = ________L
Answers…
4.51 kg = 4510 g
4 5 10Kg Hg Dg g dg cg mg
4587m = 4,587,000mm
45870 0 0m dm cm mm
1.23 mL = 0.00123 L
l dl cl ml
1 23 mL
0 0 0
Length measure distance
• The basic unit or SI unit of length in the SI system is the meter (m).• To measure objects smaller than a meter
scientists use the centimeter (cm) or the millimeter (mm)• 100 cm = 1 meter• 1000 mm = 1 meter• For larger measurements, scientists use
kilometers.• 1000 m = 1 km•Measured with a metric ruler or meter stick
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Mass measures amount of matter
• The basic unit or SI unit of mass in the SI system is the gram (g).• To measure the mass of large objects you will
use a unit known as a kilogram• It is useful in measuring the mass of bicycles, cars,
or people.• To measure the mass of smaller objects you
will use a unit known as the gram (g)•Measured with a balance or digital scale• It is useful in measuring the mass of a paper clip,
thumb tack, staple.• There are 1,000 grams in a kilogram. 11
Measuring Mass
12Triple-beam balance
Digital Scale
The Difference Between Mass and Weight•Weight is a measure of the force of gravity acting
on an object.• Measure weight by using a scale. When you stand on
a scale gravity pulls you downward. However, if you weighed yourself on the moon you would weigh less.•Mass is a measure of how much matter an object
contains, it remains constant no matter where an object may be. Your mass is the same on the moon as it is on Earth.
** The weight of an object may differ on the moon, or on earth, but the mass stays the same**
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Measuring Volume of Liquids• Volume is the amount of space an object
takes up.• To measure the volume of a liquid, you will use
a base unit or SI unit known as a liter (L).• You can measure large liquid volumes in
kiloliters (kL)• You can measure smaller liquid volumes in
milliliters (mL)• 1,000 mL = 1 L
• Measured with a graduated cylinder14
Graduated Cylinder• Scientists commonly use a graduated
cylinder to measure liquid volumes.• The graduated cylinder is marked off in
milliliter segments.•When liquid is poured into a graduated
cylinder, the top surface of the water is curved. This curve is called the meniscus. To determine the volume of the water, you should read the bottom of the meniscus
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Volume of Rectangular Solids• The basic unit or SI unit to measure the
volume of a solid object is a cubic centimeter (cm³)• A cubic centimeter is equal to the volume of a
cube that measures one centimeter on each side.• 1 cm³ = 1 mL• For solids with larger volumes, scientists use
the SI unit known as the cubic meter (m³).• A cubic meter measures one meter on each
side.• Measured with a formula:
Volume = length x width x height 16
Volume of Irregular Solids• If you wanted to find the volume of an object
that you could not determine the length, width, and height (example: rock), you would immerse the object in water and see how much the water level rises.• You would subtract the amount of water that
you started with from the amount of water that the object forced the water to rise to and you would know the volume of your object.• Known as water displacement
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Density• Density is a measure of how much mass is
contained in a given volume.
• To calculate density you divide the mass by the volume:
Density = Mass Volume
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•Because density is actually made up of two other measurements – mass and volume - an object’s density is expressed in two units. • Two common units of density are grams per
cubic centimeter (g/cm³) for regular solid items and grams per milliliter (g/mL) for irregular solid objects.• The numerator is the measure of mass while
the denominator is the measure of volume19
Density
Densities of Common Substances
Substance Density (g/cm³) Air 0.001Ice 0.9Water 1.0Aluminum 2.7Gold 19.3
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The density of an object stays the same no matter how large or small a sample of the substance is.
•An object will float if it is less dense than the surrounding liquid.•A piece of wood with the density
of 0.8g/cm³ will float in water because the density of water is 1.0 g/cm³•A ring made of pure silver with a
density of 10.5 g/cm³ will sink in water because it is more dense.
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Density
Time• Time is the period between two events• The basic unit or SI unit of time in the SI
system is the second (s).• Clocks and stopwatches are used to
measure time• Common Conversions for Time• 1s = 1,000 ms (milliseconds)• 1 min = 60 s• 1 h = 60 min
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Temperature
• The measurement of how hot or cold something is (measurement of heat)• The basic unit or SI unit of temperature in the SI
system is the Celsius scale (°C).•Water freezes at 0°C or 32°F•Water boils at 100°C or 212°F• Normal human body temperature is 37°C or 98.6°F• Temperature is measured with a thermometer.• Place the thermometer in a substance and wait for the
liquid in the thermometer to stop moving. Then read the number next to the top of the liquid in the thermometer.
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Temperature Scales
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