Pflugerville ISD - August 2005 1

Pflugerville Independent School DistrictPflugerville Independent School District

Integrated Physics & Integrated Physics & ChemistryChemistry

MeasuremeMeasurementnt

Pflugerville ISD - August 2005 2

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

5Pflugerville ISD - August 2005

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.

Pflugerville ISD - August 2005

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!