Integ. Science

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Integ. Science
Location
Due Date

• Assignments
• Take Notes Define Key Terms on 2 26
• Read/Use Appendix B
• p. A8
• Metric Homework part 1
• Metric Homework part 2

Textbook/ Notebook
Today
Textbook/ Notebook
Tuesday
Worksheet
Tuesday
Worksheet
Worksheet
Wednesday
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Precision and Accuracy
Precision indicates degree of reproducibility of
a measured number. Accuracy indicates how close
your measurements are to the true value.
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Precision and Accuracy
When making measurements in science you want them
to be both precise and accurate.
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SI Base Units
Physical Quantity Unit (standard) Symbol
Time
Length
Temperature
Mass
Volume
Amount
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SI Base and Derived Units
Physical Quantity Base Unit Symbol
length meter m
area square meter m2
mass kilogram kg
volume liter l
density gram/liter g/l
temperature degrees Celsius C
thermodynamic temperature       kelvin K
time second s
electric current ampere A
amount of substance mole mol
luminous intensity candela Cd
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Metric System

• Designed during the French Revolution of the
  1790's, the metric system brought order out of
  the conflicting and confusing traditional systems
  of weights and measures then being used in
  Europe. Prior to the introduction of the metric
  system, it was common for units of length, land
  area, and weight to vary, not just from one
  country to another but from one region to another
  within the same country.

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Metric System

• The metric system replaces all the traditional
  units, except the units of time and of angle
  measure, with units satisfying three conditions
• (1) One fundamental unit is defined for each
  quantity. These units are now defined precisely
  in the International System of Units.
• (2) Multiples and fractions of these fundamental
  units are created by adding prefixes to the names
  of the defined units.
• (3) The fundamental units are defined rationally
  and are related to each other in a rational
  fashion.
• The metric units were defined in an elegant way
  unlike any traditional units of measure. The
  Earth itself was selected as the measuring stick.
  The meter was defined to be one ten-millionth of
  the distance from the Equator to the North Pole

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Mega


kilo
hecto
deka
BASE UNIT
deci
centi
milli


micro
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Metric System

• Prefixes
• giga G 1,000,000,000 110 9
• mega M 1,000,000 110 6
• kilo k 1,000 110 3
• hecto h 100 110 2
• deka da 10 110 1
• Base Unit (meter, gram, liter, second)
  110 0
• deci d 0.1 110 -1
• centi c 0.01 110 -2
• milli m 0.001 110 -3
• micro - µ 0.000 001 110 -6
• nano n 0.000 000 001 110 -9

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Metric System

• Understanding prefixes
• Prefixes are short names and letter symbols for
  numbers (powers of ten). A prefix is attached to
  the front of a unit, without a space. Prefixes
  are easier to write and say than powers of ten,
  ordinary notation, or traditional number names.
  Compare
• 25 MW(pronounced and spelled out 25 megawatts)
• 25 X106 (the 106 is a power of ten)
• 25 000 000 W   (ordinary notation)
• 25 million watts   (traditional number name)

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Metric System

• As you go up the "ladder" of these prefixes, the
  unit is multiplied in steps of 1000, or 103.
• km 1000 X m kilometer
• Mm 1000 X km megameter
• Gm 1000 X Mm gigameter
• Going down the prefix scale, a unit is divided
  in steps of 1000. In other words, it is
  multiplied in steps of 0.001 ( 1/1000).
• mm 0.001 X m millimeter
• µm 0.001 X mm micrometer
• nm 0.001 X µm nanometer

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Metric System

• Changing prefixes by moving the decimal point
• Choose a prefix that will simplify an expression
  by eliminating unnecessary placeholding zeros
  (non-significant digits). To switch to the next
  larger prefix, move the decimal point three
  places to the left.
• 4 000 m 4 km
• 1 500 mg 1.5 g
• 500 mL 0.5 L
• 76 000 kg 76 Mg
• 2 300 µs 2.3 ms
• To switch to the next smaller prefix, move the
  decimal point three places to the right.
• 0.005 m 5 mm
• 0.009 kg 9 g
• 0.003 2 mm 3.2 µm
• When moving the decimal point to the right, you
  may have to add one or two place holding zeros at
  the end of the number to show where the
  (unexpressed) decimal point goes.
• 0.03 g 30 mg
• 0.2 L 200 mL

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Practice Problems

1. 120 mm _______________cm
2. 48.6 g _______________ cg
3. 84,000 cm _______________ Mm
4. 19.7 mm _______________m
5. 23.89 km _______________cm
6. .098 mg _______________kg
7. 29.9 Ms _______________µs

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Practice Problems

1. 421 m _______________cm
2. 486 cg _______________ Mg
3. 17,000 km _______________ Mm
4. 17 mm _______________dam
5. 23 km _______________cm
6. 225,081 mg _______________kg
7. 53 Ms _______________µs

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English Metric Conversion Tables
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Linear Measure
Imperial Imperial Metric
1 inch in 2.54 cm
1 foot ft 12 in 0.3048 m
1 yard yd 3 ft 0.9144 m
1 mile 1760 yd 1.6093 km
1 nautical mile 2025.4 yd 1.852 km

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Linear Measure Practice

• Inches to Centimeters and cm to in
• 34.3 in ??? cm 94 cm ??? in
• Feet to Meters and m to ft
• 8 ft ??? m 323 m ??? ft
• Yards to Meters and m to yd
• 100 yd ??? m 7.24 m ??? yd
• Miles to Kilometers and km to mi.
• 51.8 mi ??? km 5 km ??? mi

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Volume Measure
Imperial Imperial Metric
1 in3 Cubic Inches 16.387 cm3
1 ft3 Cubic Feet 1,728 in3 0.0283 m3
1 fl oz Fluid Ounces 23.625 ml
1 pt Pint 20 fl oz 0.4725 l
1 gal 8 pt 3.780 l

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Volume Practice

• Cubic inches to cubic centimeters
• 15 in3 ??? cm3 31.7 cm3 ??? in3
• Cubic feet to cubic meters
• 3 ft3 ??? m3 894 m3 ??? ft3
• Ounces to milliliters
• 89 oz ??? ml 89 ml ??? oz
• Gallons to liters
• 4 gal ??? L 63 L ??? gal

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Mass Measure
Imperial Imperial Metric
1 ounce oz 437.5 grain 28.35 g
1 pound lb 16 oz 0.4536 kg
1 stone 14 lb 6.3503 kg
1 hundredweight cwt 112 lb 50.802 kg
1 long ton (UK) 20 cwt 1.016 t
1 short ton (US) 2,000 lb 0.907 t
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Physical Properties

• Mass, Volume, and Density

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Mass

• What do you know about mass?

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Mass

• Measure of the amount of matter that makes up an
  object.
• Units used to designate mass are kilograms (kg)
• You can measure an objects mass using a balance
  (triple beam, electronic, spring).

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Volume

• What is Volume?

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Volume

• Volume is a measurement of the three-dimensional
  space occupied by an object.
• Units include cm3 and mL.
• Solids, liquids, and gases all have volume, but
  you measure each differently.
• Solid calculate geometrically or displacement
• Liquid measure using a graduated cylinder

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Density

• How does Density relate to Mass and Volume?

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Density

• The amount of matter in a given space.
• Does this sound familiar?
• Concentration or Compactness
• The unit for density is or .

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Mass, Volume, and Density

• Mass volume and density are directly related.
• Practice Exercise
• Measure the mass and volume of an object in the
  room.
• Calculate the Density of the Object.
• What are the units associated with this
  calculation?

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Formulae

• Density Mass / Volume
• Mass Density x Volume
• Volume Mass / Density

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Practice Problems

• Calculate the volume of an object that is 34 cm
  by 25 cm by 8 cm.
• Given V 50 mL D .75 g/mL
• Calculate Mass
• 3. Given M 55 g D 2.3 g/cm3
• Calculate Volume
• Given M .13 kg V 20 mL
• Calculate Density

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Significant Figures

• It is important to record the precision of your
  measurements so that other people can understand
  and interpret your results.
• A common convention used in science to indicate
  precision is known as significant figures.
• Significant figures are those digits in a
  measurement that are known with certainty plus
  the first digit that is uncertain.

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Significant Figures
Even though this ruler is marked in only
centimeters and half-centimeters, if you
estimate, you can use it to report measurements
to a precision of a millimeter.
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Rules for Sig Fig
Rule 1
Zeros between other nonzero digits are
significant.
Examples

1. 50.3 m has three significant figures
2. 3.0025 s has five significant figures

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Rules for Sig Fig
Rule 2
Zeros in front of nonzero digits are not
significant.
Examples

1. 0.892 has three significant figures
2. 0.0008 s has one significant figure

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Rules for Sig Fig
Rule 3
Zeros that are at the end of a number and also to
the right of a decimal point are significant.
Examples

1. 57.00 g has four significant figures
2. 2.000 000 kg has seven significant figure

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Rules for Sig Fig
Rule 4
Zeros that are at the end of a number but left of
the decimal point are not significant.
Examples

1. 100 m has ONE significant figure
2. 20 m has ONE significant figure

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Rules for Sig. Fig.
Extra Rule
Zeros that are at the end of a number but left of
the decimal point that are measured to be
significant are indeed significant.
Examples

• A scale measures 1200. kg has four significant
  figures and is written in scientific notation
• 1.200 x 10 kg so Rule 3 applies

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