Transcript Section 2A - Hollinsnet Is Now My.Hollins!

2-B
Section 2B
Standardized Units
Pages 101-112
2-B
Standardized Unit Systems
• Metric system (SI)
– Système International
• U.S. customary system (USCS)
– Roots from ancient Middle Eastern civilizations
Unit conversions within systems.
Unit conversions between systems.
2-B
U.S. Customary System - Lengths
page101
2-B
U.S. Customary System - Weights
page102
2-B
U.S. Customary System - Volumes
page102
2-B
Conversions within USCS
Ex1/103 In the Kentucky Derby, horses
race 10 furlongs. How many miles is
this?
mile
10 furlongs 
1 furlong
1
8
 1.25 miles
2-B
Conversions within USCS
Ex1/103 In 20,000 Leagues Under the Sea,
does the title refer to an ocean depth?
[convert marine leagues to miles]
3 naut.miles
20000 leagues 
 60, 000 naut. miles
1 league
6076.1 ft.
1mile
60000 naut.miles 

1 naut.mile 5280 ft
 69046.6 miles
Conversions within USCS
51’/114 If 150 bushels of wheat are traded
on one day, how many cubic inches are
traded? how many cubic feet?
2-B
International Metric System
• Invented in France, late 18th century
– Replace many customary units with
a few basic units
– Simplify conversions by using a base
10 system
2-B
International Metric System
• The basic units are:
– meter (m) for length
– gram (g) for mass
– second (s) for time
– liter (L) for volume
2-B
Metric System - Prefixes
5.23 m
523 cm
.00523 km
2-B
Conversions within Metric System
• Convert 19 decimeters to millimeters:
– conversion or decimal movement:
– 1900 millimeters
• Convert 1378 g to kg:
– conversion or decimal movement:
– 1.378 kg
2-B
USCS - Metric Conversions
USCS to Metric
Metric to USCS
1 in. = 2.540 cm
1 ft = 0.3048 m
1 cm = 0.3937 in.
1 m = 3.28 ft
1 yd = 0.9144 m
1 mi = 1.6093 km
1 lb = 0.4536 kg
1 fl oz = 29.574 mL
1 m = 1.094 yd
1 km = 0.6214 mi
1 kg = 2.205 lb
1 mL = 0.03381 fl oz
1 qt = 0.9464 L
1 L = 1.057 qt
1 gal = 3.785 L
1 L = 0.2642 gal
Conversions between Metric and USCS
60*/114 Convert 1550 millimeters to yards.
63/114 Convert 45 liters to gallons.
65/114 Convert 8550 square feet to square
meters.
67/114 Convert 10 kilograms per cubic meter to
pounds per cubic foot.
More Practice
103/117 You see oranges in an Italian
market priced at 0.8 euro per kilogram.
What is the price in dollars per pound?
105/117 A French car manufacturer claims
that its newest economy model has gas
“mileage” of 20 kilometers per liter. What
is the gas mileage in miles per gallon?
2-B
Homework
2B – Part I
Pages 113-117
#48,50,60,62,68,104,106
2-B
Temperature Units
• Fahrenheit (US)
– Water freezes at 32ºF, boils at 212ºF
• Celsius (International)
– Water freezes at 0ºC, boils at 100ºC
• Kelvin (Scientific)
– Water freezes at 273.15K, boils at 373.15K
– Coldest known temperature = 0 Kelvin
(-459.67ºF = -273.15ºC)
2-B
Converting Temperatures (page107)
To Convert from
Conversion Formula
Celsius to Fahrenheit
F = 1.8C + 32
Fahrenheit to Celsius
C = (F-32)/1.8
Celsius to Kelvin
K = C + 273.15
Kelvin to Celsius
C = K - 273.15
2-B
Example
Ex6/108 A ‘normal’ human temperature is
98.6ºF What is that in Celsius and Kelvin?
F  32
C
1.8
98.6-32 66.6


 37
1.8
1.8
K  C  273.15  37  273.15  310.15
98.6o F = 37o C = 310.15o K
2-B
Energy and Power
• Energy is what makes matter move or heat up.
•
The international unit of energy is the joule.
Power is the rate at which energy is used. The
international metric unit of power is the watt,
defined as
joule
1 watt  1
second
• A kilowatt-hour is a unit of energy and
1 kWh = 3600000 joules = 3.6 million joules
1 kw x 1hr = 1000j/s x 60s/m x 60m/hr x 1 hr
2-B
93/116 Your refrigerator uses an average
power of 350 watts, and your utility
company charges 10 cents per kilowatthour of energy. How much does it cost to
run your refrigerator for a year?
Conversion:
350 watts is .350 kilowatts (why?)
Usage per year in kilowatt-hours:
.350 kilowatts x 24 hours/ 1 day x 365 days/1 year
= 3066 kilowatt-hours / year
Cost per year:
3066 kilowatt-hours / year x .10 $ / 1 kilowatt-hour
= 306.60 $ per year
2-B
Units of Density/Concentration
• Density (e.g. material, population) – describes
compactness or crowding.
– material: mass/volume (g/cm3)
– Population: people/mi2
• Concentration (e.g. pollutants, BAC) describes the
amount of one substance mixed with another.
– pollutants: ppm
– BAC: g/100mL (legal limit is 0.08g/100mL)
2-B
Example
Ex9/111-2 Manhattan Island has a population of ≈
1.5 million people living in an area of about 57
km2. What is its population density? How much
space is available per person?
people
density 
area
1,500,000people

57 km2
 26,000 people
km2
2-B
Example
(for fun)
Ex9/111-2(cont.) How much space is that per person?
1km2
26,000people
1km2
1000m 1000m



26,000people 1 km
1 km
 38m2 / person
Which is roughly 6m×6m, or 20 ft × 20 ft
2-B
Example
Ex10/112 An average-sized man has about 5L of
blood, and an average 12-ounce beer contains
15g of alcohol. If all the alcohol were
immediately absorbed into the bloodstream,
what would his BAC be?
15 g alcohol
concentration 
5000mL blood
g
 .003
mL
 .003
g
mL

100
100
 0.3
g
100mL
More Practice
79/114 The land area of the US is about 3.5 million
square miles, and the population is about 280
million people. What is the average population
density?
83/114 A typical glass of wine contains about 20
grams of alcohol. Consider a 110-pound woman,
with approximately 4 liters of blood who drinks
two glasses of wine. Assuming immediate
absorption, what is her BAC?
2-B
Homework
2B – Part II
Pages 113-117
#70, #72, #80, #84, #94