pflugerville isd - august 20051 pflugerville independent school district integrated physics &...
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Pflugerville ISD - August 2005 1
Pflugerville Independent School DistrictPflugerville Independent School District
Integrated Physics & Integrated Physics & ChemistryChemistry
MeasuremeMeasurementnt
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Quantitative and Qualitative ObservationsWhat do YOU thinkthe difference is?
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1) What is a system of measurement ?
2) Metric system- AKA International system , and SI (Systeme International d'Unites)
English system- AKA British system, customary system & “our” system
3, 4, 5, 6) METRIC!!!!!!
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7 Base Metric Units• Meters measure length
• Kilograms measure mass
• Seconds measures time
• Kelvin measures temperature
• Ampere measures current• Lumens measures light intensity
• Moles measures the amount of a substance
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Metric Prefixes
Kilo = 1000
Hecto = 100
Deka = 10
Deci = 1/10
Centi = 1/100
Milli = 1/1000
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Other Derived Metric Units (from basic 7)
• Volume is length x width x height measured in centimeters cubed or millilters
• Temperature is measured in degrees celsius or centigrade (oC)
• Heat is measured in calories (cal) or joules (J)
• Weight is measured in newtons (N)
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How Big? A meter is about 39 inches A kilometer is 0.6 mile A centimeter is about the width
of your little finger A gram is about the mass of a
paper clip A kilogram is 2.2 pounds You drink 2 liters of popSee handout for other prefixes
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Tools for Measurement
• Meterstick• Balance (triple
beam and digital)• Graduated
Cylinder• Stopwatch
• Thermometer
• Multimeter
• Photometer
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Graduated CylinderMeasurement
• Volume is measured using a graduated cylinder.
• When reading a graduated cylinder, read the bottom of the meniscus.
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10
Insert Slides on Dimensional Analysis
From Bill Anderson, HHS
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K H D O D C M To change from one metric unit
to another, we simply multiply by a conversion factor.
For example: 25.4 km = _____________ cm?
25.4 km x 1000cm/1km = 2,540,000 cm
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Scientific Notation Rules:
1 digit before the decimal point Multiply the number by a power
of 10 Example: Write 34,000 in
scientific notation. Solution: 3.4 x 104
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Write the following in scientific notation:
4,100,000 = _______________ 345,600,000,000 =
_________ 0.0456= ________________ 0.00000012=____________ O.00305= ____________
4.1 x 106
3.456 x 1011
4.56 x 10-2
1.2 x 10-7
3.05 x 10-3
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Write the following in standard form:
4.67 x 103 =__________________ 3.112 x 105 = _________________ 3.112 x 10-4 = ________________ 4 x 10-6 = ___________________ 1 x 1011 = __________________
46703112000.0003112
0.000004100,000,000,000
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Density of Water One milliliter of
water Has a mass of 1
gram Density = Mass ÷
Volume Calculate the
density of water
1g ÷ 1mL = 1g/mL
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Measuring Water If you
wanted to measure 25 mL of water, what instrument would you use?
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Measuring Water
If you wanted to measure 25 grams of water, what 2 instruments could you use?
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Accuracy vs. Precision ACCURACY "capable of
providing a correct reading or measurement.”
A measurement is accurate if it correctly reflects the size of the thing being measured.
PRECISION "exact, as in
performance, execution, or amount.”
It means repeatable, reliable, getting the same measurement each time.
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Try This On-line Activity
http://www.learner.org/channel/courses/learningmath/measurement/session2/part_c/accuracy.html
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
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Measuring volume of a solid by water displacement
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One cubic centimeter = One milliliter
This cube’s sides areeach 3 cm. What is the volume of the cube?
Using water displacement,how many milliliters do you expect the waterto raise when the cubeis lowered?
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That’s all folks!That’s all folks!
Time to try some on your own!Time to try some on your own!