Section 2B Standardized Units Standardized Units Pages B

Standardized Unit Systems  Metric system (SI) Système International Système International  U.S. customary system (USCS) Roots from ancient Middle Eastern civilizations Roots from ancient Middle Eastern civilizations  Unit Conversions within systems  Unit Conversions between systems 2-B

U.S. Customary system – Lengths page B

U.S. Customary system – Weights page B

U.S. Customary system – Volumes page B

Example :  In the Kentucky Derby, horses race 10 furlongs. How many miles is this? 2-B

Conversions within USCS In 20,000 Leagues Under the Sea, does the title refer to an ocean depth? 2-B [convert marine leagues to miles]

Conversions within USCS If 150 bushels of wheat are traded on one day, how many cubic inches are traded?

International Metric System  Invented in France, late 18 th century Replace many customary units with a few basic units Replace many customary units with a few basic units Simplify conversions by using a base 10 system Simplify conversions by using a base 10 system 2-B

International Metric System  The basic units are: meter (m) for length meter (m) for length kilogram (kg) for mass kilogram (kg) for mass second (s) for time second (s) for time liter (L) for volume liter (L) for volume 2-B

Metric system - Prefixes Moving between metric units requires shifting the decimal place one to the right when going to the next smaller unit and one to the left when going to the next larger unit. (Example: 5.23 cm = 52.3 mm) 2-B

Examples  Convert 19 decimeters to millimeters: Move the decimal 2 places to the RIGHT: Move the decimal 2 places to the RIGHT: 1900 millimeters 1900 millimeters  Convert 1378 g to kg: Move the decimal 3 places to the LEFT: Move the decimal 3 places to the LEFT: kg kg 2-B

USCS - Metric Conversions USCS to Metric Metric to USCS 1 in. = cm 1 cm = in. 1 ft = m 1 m = 3.28 ft 1 yd = m 1 m = yd 1 mi = km 1 km = mi 1 lb = kg 1 kg = lb 1 fl oz = mL 1 mL = fl oz 1 qt = L 1 L = qt 1 gal = L 1 L = gal 2-B

Conversions between Metric and USCS Convert 20 gallons to liters.

Conversions between Metric and USCS Convert 105 centimeters to yards..

Temperature Units  Fahrenheit Water freezes at 32ºF, boils at 212ºF Water freezes at 32ºF, boils at 212ºF  Celsius Water freezes at 0ºC, boils at 100ºC Water freezes at 0ºC, boils at 100ºC  Kelvin Water freezes at K, boils at K Water freezes at K, boils at K Coldest known temperature = 0 Kelvin Coldest known temperature = 0 Kelvin ( ºF = ºC) 2-B

Converting Temperatures page B To Convert fromConversion Formula Celsius to Fahrenheit F = 1.8C + 32 Fahrenheit to CelsiusC = (F-32)/1.8 Celsius to KelvinK = C Kelvin to CelsiusC = K

You try  A ‘normal’ human temperature is 98.6ºF What is that in Celsius, and Kelvin? 2-B

Question?  A local weather report says that tomorrow’s high temperature will be 52º, but does not specify whether the units are Fahrenheit or Celsius.  Can you tell which it is? How? 2-B

Energy and Power  Energy is what makes matter move or heat up. The international metric 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 2-B

Energy & Power  A kilowatt-hour is a unit of energy:  1 kilowatt-hour = 3.6 million joules 2-B

 According to my electric bill my total electrical energy usage during the past 12 months was 19,227 KWH.  And, I was charged (roughly) $.032/KWH.  How much did I spent on power in the last year? 2-B

Units of Density/Concentration  Density – describes compactness or crowding. g/cm 3, people/mi 2 g/cm 3, people/mi 2  Concentration describes the amount of one substance mixed with another. ppm, g/100mL (BAC) ppm, g/100mL (BAC) For most states – legal limit is 0.08g/100mLFor most states – legal limit is 0.08g/100mL 2-B

Example  Manhattan Island has a population of ≈ 1.5 million people living in an area of about 57 km 2. What is its population density? How much space is available per person? 2-B

Example  How much space is that per person?  Which is roughly 6m×6m, or 20ft × 20 ft. 2-B

Example  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? 2-B

More Practice A boat is moving at 30 knots (nautical miles per hour). How fast is this in miles per hour?

More Practice Eight ounces of hard liquor typically contain about 70g of alcohol. Consider a 200lb man, with approx. 6 liters of blood, who quickly drinks 8 oz. of hard liquor. If all the alcohol were immediately absorbed into his bloodstream, what would his BAC be?

More Practice Now assume his body eliminates the alcohol through metabolism at the rate of 15g/hr. What is his BAC 4 hours after drinking the liquor? Is it safe for him to drive at this time?

Homework for Wednesday Pages # 14, 40, 58, 60a,b,c, 71, 73, 94 2-B