slide 8-1 copyright © 2005 pearson education, inc. seventh edition and expanded seventh edition
TRANSCRIPT
Slide 8-1 Copyright © 2005 Pearson Education, Inc.
SEVENTH EDITION and EXPANDED SEVENTH EDITION
Copyright © 2005 Pearson Education, Inc.
Chapter 8
The Metric System
Copyright © 2005 Pearson Education, Inc.
8.1
Basic Terms and Conversions within the Metric System
Slide 8-4 Copyright © 2005 Pearson Education, Inc.
SI System and U.S. Customary System
Most countries of the world use the SI system The SI system is referred to as the metric
system in the United States. Two systems of weights and measures exist
side by side in the United States today, U.S customary system and the metric system.
Slide 8-5 Copyright © 2005 Pearson Education, Inc.
Advantages to Using the Metric System
The metric system is the worldwide accepted standard measurement system.
There is only one unit of measurement for each physical quantity.
The SI system is based on the number 10, allowing less need for fractions.
Slide 8-6 Copyright © 2005 Pearson Education, Inc.
Basic Terms
a little more than a quart
volumeLliter
about 2.2 pounds
masskgkilogram
a little more than a yard.
lengthmmeter
Comparison to Customary
Common UseAbbrev.Metric
Term
Slide 8-7 Copyright © 2005 Pearson Education, Inc.
Metric Prefixes
of base unitmmilli
of base unitccenti
of base unitddeci
base unit
10 base unitdadeka
100 base unithhecto
1000 base unitkkilo
MeaningSymbolPrefix
110
11001
1000
Slide 8-8 Copyright © 2005 Pearson Education, Inc.
Changing Units within the Metric System To change from a smaller unit to a larger unit move
the decimal point in the original quantity one place to the left for each larger unit of measure until you obtain the desired unit of measure.
To change from a larger unit to a smaller unit, move the decimal point in the original quantity one place to the right for each smaller unit of measurement until you obtain the desired unit of measure.
Slide 8-9 Copyright © 2005 Pearson Education, Inc.
Example: Changing Units
Convert 54.6 m to km. Convert 15 L to mL. Convert 0.89 kg to cg.Solutions: Meters is a smaller unit than km. Move the decimal 3
places to the left, 0.0546. Liter is a larger unit than milliliter. Move the decimal
point 3 places to the right, 15,000. 0.89 kg = 89,000 cg
Slide 8-10 Copyright © 2005 Pearson Education, Inc.
Example: Application
A case of fruit juice contains twenty-four 0.75 liter bottles. How many 250 milliliter glasses can you fill using one case of juice?
Solution: The case of juice contains
24(0.75) = 18 L.
Converting 18 L = 18,000 mL. If each glass hold 250 mL, then glasses can be filled.18,000
72250
Copyright © 2005 Pearson Education, Inc.
8.2
Length, Area, and Volume
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Length
The meter is used to measure things that we normally measure in yards and feet.
Centimeters and millimeters are used to measure what we normally measure in inches. A centimeter is a little less than a half of an inch. A millimeter is about the thickness of a dime.
Example: The length of a pair of scissors would be measured in centimeters.
Slide 8-13 Copyright © 2005 Pearson Education, Inc.
Area
Areas are always expressed in square units.
Example: The length of a rectangular park is 82.5 m, and its width is 25.4 m. Find the area of the park.
Solution: Area = length width.
2
82.5 25.4
2095.5 m
A
A
Slide 8-14 Copyright © 2005 Pearson Education, Inc.
Volume
When a figure has three dimensions; length, width and height, the volume can be found.
The volume of an item can be considered the space occupied by the item.
Volume can be expressed in terms of liters or cubic meters.
1 m3 = 1 kL
1 dm3 = 1 L
1 cm3 = 1 mL
Volume in LitersVolume in Cubic Units
Slide 8-15 Copyright © 2005 Pearson Education, Inc.
Volume
When the volume of a liquid is measured, the abbreviation cc is often used instead of cm3 to represent cubic centimeters.
Example: An asthma patient must mix 0.25 cc of a bronchodilator with 2 cc of saline to use in an aerosol machine.
How many milliliters of the bronchodilator will be administered?
What is the total volume of drug and saline solution in milliliters?
Slide 8-16 Copyright © 2005 Pearson Education, Inc.
Volume continued
Solution: Since 1 cc is equal in volume to 1 milliliter,
there will be 0.25 milliliters of the bronchodilator.
The total volume is 0.25 + 2 or 2.25 cc, which is equal to 2.25 mL.
Slide 8-17 Copyright © 2005 Pearson Education, Inc.
Example: Volume Application
A cylindrical shampoo bottle has a diameter of 6 cm and a height of 12 cm. What is the volume in milliliters?
Solution:
2
2
3
3.14 3 12
339.12 cm
339.12 mL
V r h
V
V
V
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8.3
Mass and Temperature
Slide 8-19 Copyright © 2005 Pearson Education, Inc.
Mass
Although weight and mass are not the same, on Earth they are proportional to each other. Mass is a measure of the amount of matter in an
object. Weight is the measure of gravitational pull on an
object.
Slide 8-20 Copyright © 2005 Pearson Education, Inc.
Metric System
The kilogram is the basic unit of mass in the metric system. Example: A man has the mass of about 75 kg.
The gram is relatively small and used in place of the ounce. Example: A nickel has the mass of about 5 g.
The milligram is used in the medical and scientific fields. The metric tonne is used to express mass of heavy
items. One metric tonne = 1000 kg.
Slide 8-21 Copyright © 2005 Pearson Education, Inc.
Example: Choosing an Appropriate Unit Determine which metric unit you would use to express
the mass of the following.
a) A spider c) A bicycle
b) A nickel d) A nickel
Solution:
a) Milligrams c) Kilograms
b) Grams d) Grams
Slide 8-22 Copyright © 2005 Pearson Education, Inc.
Volume and Mass of Water
Volume in Cubic Units
1 m3 = 1 kL = 1 t (1000 kg)
1 dm3 = 1 L = 1 kg
1 cm3 = 1 mL = 1 g
Mass of WaterVolume in Liters
Slide 8-23 Copyright © 2005 Pearson Education, Inc.
Example: Capacity
A fish tank is 1 m long, 60 cm high and 260 mm wide.
Determine the number of liters that the tank holds.
What is the mass of the water in kilograms.
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Example: Capacity continued
Solution:
Since 1 m3 of water = 1 kL of water,
0.156 m3 = 0.156 kL, or 156 liters of water Since 1L = 1 kg, 156 L = 156 kg of water.
3
1 0.26 0.6
0.156 m
V l w h
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Temperature
The term degrees Celsius is used to measure temperature.
C
Water boils212100
Body temperature98.637
Comfortable room71.622
Water freezes320
Description
Temperature
C F
C
C
C
C F
F
F
F
Slide 8-26 Copyright © 2005 Pearson Education, Inc.
Example: Choose or
The temperature of a can of frozen juice about 2 __.
The temperature of a person with a fever is about 101.5 __.
The temperature of a bowl of hot soup is about 175 __.
Solution: a) b) c)
F .C
.C F F
Slide 8-27 Copyright © 2005 Pearson Education, Inc.
Conversions
To covert from Celsius to Fahrenheit use the following formula.
To covert from Fahrenheit to Celsius use the following formula.
9F C 32
5 5
C F 329
Slide 8-28 Copyright © 2005 Pearson Education, Inc.
Example: Conversions
The air temperature on a warm summer day is about 85 . What is the equivalent temperature on the Celsius thermometer?
Solution:
The equivalent temperature is about 29.4
5C F 32
95
C 85 3295
C 53929.4C
.C
F
Slide 8-29 Copyright © 2005 Pearson Education, Inc.
Example: Conversions
The temperature of a cold glass of milk is about 5 . What is the equivalent temperature on the Fahrenheit thermometer?
Solution:
The equivalent temperature is about
41
C
9F C 32
59
F 5 325
F 9 32
F 41
.F
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8.4
Dimensional Analysis and Conversions to and from the
Metric System
Slide 8-31 Copyright © 2005 Pearson Education, Inc.
Dimensional Analysis
Dimensional analysis is a procedure used to convert from one unit of measurement to a different unit of measurement.
A unit fraction is any fraction in which the numerator and denominator contain different units and the value of the fraction is 1.
Examples of unit fractions:
16 oz 1 hr 12 in.
1 lb 60 min 1 ft
Slide 8-32 Copyright © 2005 Pearson Education, Inc.
U.S. Customary Units
1 pint = 2 cups
1 year = 365 days1 cup (liquid) = 8 fluid ounces
1 day = 24 hours1 ton = 2000 pounds
1 hour = 60 minutes1 pound = 16 ounces
1 minute = 60 seconds1 mile = 5280 feet
1 gallon = 4 quarts1 yard = 3 feet
1 quart = 2 pints1 foot = 12 inches
U.S. Customary Units
Slide 8-33 Copyright © 2005 Pearson Education, Inc.
Example: Using Dimensional Analysis
A recipe calls for 8 cups of blueberries. How many pints is this?
Solution:
Convert 75 miles per hour to inches per minute.Solution:
1 pint8 cups = 8 cups 4 pint s
2 cups
75 5280 12mi mi 5280ft 12 in 1 hr in75 75
hr hr 1 mi 1 ft 60 min 60 min
in = 79,200
min
Slide 8-34 Copyright © 2005 Pearson Education, Inc.
Conversion to and from the Metric System
Slide 8-35 Copyright © 2005 Pearson Education, Inc.
Example: Volume and Area
A gas tank holds 22.6 gallons of gas. How many liters is this?
Solution:
The area of a box is 14.25 in2. What is its area in square centimeters?
Solution:
3.8 L22.6 gal = 85.88 L
gal
22 2
2
6.5 cm14.25 in 92.625 cm
1 in
Slide 8-36 Copyright © 2005 Pearson Education, Inc.
Example: Converting Speed
A road in Toronto, Canada shows that the speed limit is 62 kph. Determine the speed in miles per hour.
Solution:
Since 62 km equals 38.75 mi, 62 kpm is equivalent to 38.75 mph.
1 mi 6262 km mi 38.75 mi
1.6 km 1.6
Slide 8-37 Copyright © 2005 Pearson Education, Inc.
Example: Weight (Mass) Conversion for Medication A newborn baby weighs 8 pounds 4 ounces. If 20 mg of
a medication is given for each kilogram of the babies weight, what dosage should be given?.
Solution:
The dosage of the medication is 73.92 mg.
16 oz8 lbs 128 oz 4 oz 132 oz
1 lb
28 g 1 kg 20 mg132 oz 3.696 kg 73.92 mg
oz 1000 g 1 kg