Technical Science Scientific Tools and Methods

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Technical ScienceScientific Tools and Methods

• The Metric System
• Modified from http//www.swtc.edu8082/mscenter/mt
  hsci/science/1tools/p02amtrc.pps

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The Metric System

• In this section you will
• Describe the features of a measurement system
• Describe the benefits of the Metric System
• Make metric conversions
• Make metric measurements

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Measurement Systems
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• Any measurement system will have three features.

• Standard Units
• Additional units for measuring large and small
  quantities
• Relationships between units of measure

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Measurement Systems
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• Standards are units of measure that are the same
  no matter where you go.

• A foot represents the same distance everywhere in
  the US. A foot is a standard unit of length.
• Since everyone agrees on the value of a standard,
  they insure that measurements are consistent.

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Measurement Systems

• You will want to make other measurements besides
  length. A standard is necessary for each type of
  measure you want to make.

Measurement English Metric Length Foot Meter W
eight Pound Gram Capacity Gallon Liter etc
etc etc
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Measurement Systems

• A foot is a standard unit of length. But, it is
  not a good unit for measuring all lengths.

• You could measure the room or a table in feet.
  But it would not make sense to measure a blood
  cell or the distance between two cities in feet.
• A measurement system must have additional units
  to measure very large and very small amounts.

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Measurement Systems

• What are some of the additional units of measure
  for length, weight, and capacity in the English
  system?

Length Inch, Foot, Yard, Mile,
etc Weight Ounce, Pound, Ton, etc Capacity Cup,
Pint, Quart, Gallon, Barrel, etc
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Measurement Systems

• Finally, measurement systems must have
  relationships between the units of measure.

• Since inches, feet, yards, and miles are all
  measurements of length then you should be able to
  convert from one to another.
• There are 12 inches in one foot. There are 3
  feet in one yard. There are 1760 yards in a
  mile. These relationships are constant. This
  allows us to convert from one unit to another.

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Measurement Systems
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• What are the three requirements for a measurement
  system?

• There must be standards for every type of
  measurement you want to make.
• There must be additional units for measuring
  large and small quantities.
• There must be a relationship between the units of
  measure.

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Benefits of the Metric System
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• Any measurement system will have three features
• Standard Units
• Additional units for measuring large and small
  quantities
• Relationships between units of measure

• If both the English system and the Metric system
  have all the requirements for a measuring system,
  why should we switch to the metric system?
• To answer this question, lets see how convenient
  the English system is to work with.

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Benefits of the Metric System

• Lets say you were asked the following question
  How many inches are in one mile?

• To answer this question you would need some of
  the information that follows.
• 12 inches 1 foot 3 feet 1 yard
• 5280 feet 1 mile 1760 yards 1 mile
• Now you can see one problem with the English
  system. There is no consistent relationship
  between the units in the English system.

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Benefits of the Metric System

• The Metric system has a consistent relationship
  between units.

• This means that as you move from one unit to the
  next larger or smaller you always change by the
  same factor.
• In the Metric system the factor by which you
  change is 10. This makes the Metric system a
  base-ten system.

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• Another benefit of the Metric System is the fact
  that that the whole world uses it. (except the
  US)

• All fields of science use only the Metric System.

• In order for a measurement system to be useful
  everyone must agree on the standards that make it
  up.
• The more people that agree on those standards the
  better the system will be.

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Making Metric Conversions
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• Study the table below to become familiar with
  metric units of measure.

Back
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Making Metric Conversions

• Answer the following questions. Use the button
  below to refer to the Table of Metric Prefixes.

• What is the base unit of measure for ...
• Length
• Mass
• Volume

• Meter
• Gram
• Liter

Table
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Making Metric Conversions

• Name the following units of measure. Use the
  prefix followed by the base unit.
• 1,000 meters
• 0.001 liters
• 0.000001 grams
• 0.01 meters
• 10 gram
• 1,000,000 bytes

• Kilometer
• Milliliter
• Microgram
• Centimeter
• Dekagram
• Megabyte

Table
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Making Metric Conversions

• You probably noticed that the metric prefixes
  stay the same no matter what unit of measure you
  use.

• Length in the English system is measured in
  inches, feet, yards, miles etc. but volume is
  measured in ounces, cups, quarts, gallons, etc.
• In the metric system kilo is always 1,000 base
  units. It doesnt matter what you are
  measuring.
• 1000 grams is a kilogram. 1000 watts is a
  kilowatt.
• There are a lot less metric units to remember.
• This is another benefit of the Metric System.

Table
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Making Metric Conversions

• Name the unit when given the abbreviation and
  vice versa. Metric abbreviations use small case
  letters (except mega and giga) and no periods.
• km Mililiter
• mg Kilogram
• cm Nanometer
• Mg Decimeter
• ug Dekagram

• Kilometer
• Milligram
• Centimeter
• Megagram
• Microgram

• ml
• kg
• nm
• dm
• dkg

Table
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Making Metric Conversions

• Now that you are familiar with metric units, you
  can make some conversions.

• To make conversions within the Metric System, you
  have to answer two questions.
• First, how many positions is it from the starting
  unit to the unit you want to convert to? Since
  the metric system is base ten, this tells how
  many places to move the decimal.
• Second, are you converting from a larger unit to
  a smaller unit or from a smaller unit to a larger
  unit? This tells which way to move the decimal.
  

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Making Metric Conversions
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• Make the following metric conversions.
• 1,000 grams kg
• 500 mg g
• 2.25 liters ml
• 0.07 g kg
• 1 kilometer m
• 450 ul ml
• 75 cm um
• 650 cm m
• 0.30 kg mg

• 1
• 0.5
• 2250
• 0.00007
• 1000
• 0.450
• 750,000
• 6.5
• 300,000

Table
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Making MetricMeasurements
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• Now you can make metric conversions but can you
  answer the questions below?

• You need 5 kilograms of potatoes from the store,
  can you carry them or should you take your car?
• A label on a bottle of cough syrup reads give 5
  milliliters as needed. Will 5 milliliters fit in
  a teaspoon or will you need a tablespoon?
• You are running a 1600 meter race. Is this a
  sprint or a distance event?

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Making MetricMeasurements - Length

• The following are approximations to help you get
  a feel for metric units of length. We will deal
  only with the most common units.

• 1 kilometer ? Just over one half mile
• 1 meter ? Just over one yard
• 1 centimeter ? Width of your little fingernail
• 1 millimeter ? Thickness of your fingernail
• 1 micrometer ? Diameter of a bacteria

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Making MetricMeasurements - Length

• Choose the most appropriate measure.

• Length of a football field
• 1 km, 100 m, 1,000 um, 10 cm, 100 mm
• Length of a newborn baby
• 0.5 m, 0.05 km, 500 um, 5,000mm, 50 cm
• Thickness of a sheet of paper
• 0.1 mm, 0.1 cm, 0.01 m, 1 km, 10 um

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Making Metric Measurements - Length

• The diagram below is part of a metric tape
  measure. The numbered divisions are centimeters.
  The small divisions are millimeters

• 10 Millimeters
• 100 Centimeters
• No
• Too large

• How many millimeters are in 1 cm?
• How many centimeters are in 1 m?
• Is the diagram drawn to scale?
• Are the units too large or too small?

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Making Metric Measurements - Length
A

• Measure Line A in mm, cm, and m. (Hint make
  your initial measurement in mm then convert.)

• You have gone 99 cm and 2 mm.

• 99 cm 990 mm

• 2 mm

• 992 mm

• 99.2 cm

• 0.992 m

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Making Metric Measurements - Length
B

• Measure Line B in mm, cm, and m.

• You have gone 1 m, 2 cm, and 7 mm.
  

• 1m 100 cm 1000 mm

• 2 cm 20 mm

• 7 mm

• 1027 mm

• 102.7 cm

• 1.027 m

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Making Metric Measurements - Length
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2

• Measure Line 1 and 2 in mm, cm, and m.

• 1004 mm

• 100.4 cm

• 1.004 m

• Line 1
• Line 2

• 979 mm

• 97.9 cm

• 0.979 m

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Making Metric Measurements - Length
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4

• Measure Line 3 and 4 in mm, cm, and m.

• 2015 mm

• 201.5 cm

• 2.015 m

• Line 3
• Line 4

• 1998 mm

• 199.8 cm

• 1.998 m

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Making MetricMeasurements - Mass

• The following are approximations to help you get
  a feel for metric units of mass. We will deal
  only with the most common units.

• 1 kilogram ? Just over 2 pounds
• 1 gram ? Mass of a raisin
• 1 milligram ? Mass of a grain of sand

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Making MetricMeasurements - Mass

• Choose the most appropriate measure.

• Mass of a nickel
• 50 g, 5 mg, 0.5 kg, 5 g, 500 mg
• Mass of an aspirin
• 500 mg, 0.5 mg, 500 g, 50 kg, 50 g
• Mass of an average adult
• 700 kg, 0.7 g, 700 mg, 7,000 g, 70 kg
• Mass of a baseball
• 400 mg, 0.4 g, 4 kg, 400 g, 40 g

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Making MetricMeasurements - Volume

• The following are approximations to help you get
  a feel for metric units of volume. We will deal
  only with the most common units.

• 1 liter ? Just over 1 quart
• 1 milliliter ? About 20 drops

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Making MetricMeasurements - Volume

• Choose the most appropriate measure.

• Volume of a cars gas tank
• 50 l, 5 l, 500 ml, 50 ml, 500 l
• Volume of a teaspoon
• 0.5 l, 0.5 ml, 5 l, 5 ml, 500 ml
• Volume of a can of soda
• 500 l, 0.05 l, 500 ml, 0.5 ml, 0.005 ml
• Volume of a syringe
• 0.02 ml, 200 ml, 0.02 l, 2 l, 2 ml

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Making Metric Measurements - Volume

• Volume can be measured using beakers that are
  designed to hold a standard amount of fluid.

• 1000 Milliliters
• False

• How many milliliters are in 1 liter?
• Do the small divisions represent the same volume
  on each beaker?

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Making Metric Measurements - Volume

• Measure the volume of water in the beaker in ml
  and l

• There are 5 divisions between 0 ml and 250 ml.
• Each division is 50 ml (250 ? 5).

• You have gone past 500 ml and 2 more divisions.

• 500 ml

• 2 divisions 100 ml

• 600 ml

• 0.6 liters

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Making Metric Measurements - Volume

• Measure the volume of water in the beaker in ml
  and l

• There are 5 divisions between 0 ml and 50 ml.
• Each division is 10 ml (50 ? 5).

• You have gone past 50 ml and 4 more divisions.

• 50 ml

• 4 divisions 40 ml

• 90 ml

• 0.09 liters

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Making Metric Measurements - Volume
1

• Measure the volume of water in Beakers 1 2 in
  ml and l

• 60 ml

• 0.06 liters

• Beaker 1
• Beaker 2

2

• 850 ml

• 0.850 liters

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Making MetricMeasurements
Home

• Name at least three benefits of the Metric
  System.

• There is a consistent relationship between units.
  Prefixes stay the same.
• There arent a lot of conversion factors to
  remember. Its easy to convert.
• The whole world uses it.