DIFFICULTY OF THE IMPERIAL UNITS?

DIFFICULTY OF THE IMPERIAL UNITS One inch is usually divided into 8, 10 or 16 parts: This particular ruler has 16 divisions

DIFFICULTY OF THE IMPERIAL UNITS One inch is usually divided into 8, 10 or 16 parts: So, the smallest division = 1/16th of an inch

What is the length of the pencil? One inch is usually divided into 8, 10 or 16 parts: So, the smallest division = 1/16th of an inch

One inch is usually divided into 8, 10 or 16 parts: What is the length of the pencil? One inch is usually divided into 8, 10 or 16 parts:

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1.3 Relating SI and Imperial Units Copyright © 2010 Ryan P. Murphy

Copyright © 2010 Ryan P. Murphy

I will show you these 6 pictures showing you their metric values. Mph (Miles per hour) Gallon Pounds Yards Fahrenheit Inches

One gallon of milk = 3.78 liters of milk

65 mph = 104 km/h Copyright © 2010 Ryan P. Murphy

Double Quarter Pounder(0.5 pound) = 0.226 kg

48 inches tall = 1.22 meters tall Copyright © 2010 Ryan P. Murphy Copyright © 2010 Ryan P. Murphy

1 Yards = 0.914 meters Copyright © 2010 Ryan P. Murphy

80 degrees Fahrenheit = 26.7 degrees Celsius Copyright © 2010 Ryan P. Murphy

The International System (System Internationale ‘unites) of Units (SI) also known as THE METRIC SYSTEM.

It is used by scientists all over the world

The Metric System: A measurement system based on the powers of ten. Copyright © 2010 Ryan P. Murphy

POWERS OF TEN HAVE PREFIXES Copyright © 2010 Ryan P. Murphy

YOU MUST KNOW THEM!!! Copyright © 2010 Ryan P. Murphy

Only one unit of measurement for each quantity The simplicity of the Metric System? For example: LENGTH: meter MASS: gram VOLUME: liter Only one unit of measurement for each quantity Copyright © 2010 Ryan P. Murphy

You can measure the very small and the very large with the same unit meter Copyright © 2010 Ryan P. Murphy

The measurements below are all the same. “I am 1828.80 mm tall.” “I am 182.80 cm tall.” “I am 1.8280 meters tall.” “I am .001828 km tall.” Compare it with Imperial System Copyright © 2010 Ryan P. Murphy

Only one unit of measurement for each quantity The simplicity of the Metric System? SI For example: LENGTH: meter MASS: gram VOLUME: liter Only one unit of measurement for each quantity Imperial For example: LENGTH: mile, yard, foot/feet, inch… MASS: grain (≈0.65g), drachm (1.77 g), pound (453 g)… VOLUME: ounce (0.028 L), gill (0.142 L), gallon (4.55 L)… Copyright © 2010 Ryan P. Murphy

Dimensional Analysis and Conversion factors

We can do this using 2 methods: Any quantity we measure,(length, mass, volume…) consists of a number and unit 22.2 m If we are given a quantity in one type of unit, and we want another type of unit : 22.2 m = ? ft We must convert the units We can do this using 2 methods:

OR

A relationships between any quantities can be expressed by CONVERSION FACTORS

A relationships between any quantities can be expressed by CONVERSION FACTORS

EXAMPLE #1 Convert 21.5 inches to cm!

EXAMPLE #1 Convert 21.5 inches to cm! Step 1: Write conversion factors for inches and cm Step 2: Choose a conversion factor which will allow you to cancel units of a given quantity (inches in our case) Step 3: Multiply, cancel and check the units

Convert 21.5 inches to cm! Step 1: Write conversion factors for inches and cm  

Convert 21.5 inches to cm! Step 1: Write conversion factors for inches and cm   Step 2: Choose a conversion factor which will allow you to cancel units of a given quantity (inches in our case)

Step 3: Multiply, cancel and check the units Convert 21.5 inches to cm! Step 3: Multiply, cancel and check the units 𝟏 𝒊𝒏𝒄𝒉 𝟐.𝟓𝟒 𝒄𝒎 NO! 21.5 inches x 𝟐.𝟓𝟒 𝒄𝒎 𝟏 𝒊𝒏𝒄𝒉 YES! 21.5 inches x 1 𝑖𝑛𝑐ℎ 2.54 𝑐𝑚 2.54 𝑐𝑚 1 𝑖𝑛𝑐ℎ

1 step metric conversion EXAMPLE #1 Convert 21.5 inches to cm! 1 step metric conversion

A Canadian football field is approximately 59 m wide A Canadian football field is approximately 59 m wide. What is this measurement to the nearest foot? Use both of the methods of conversion. a) 192 ft. a) 192 ft.

Nora knows that she is 5 ft. 7 in. tall. a) What height in centimetres will she list on her driver’s license application? Use both of the methods of conversion. a) 170 cm

HOMEWORK Pages: 22 – 23 Problems: 4 – 14 (all even)

Convert 6.32 µm to km Convert to a base unit (need 2 conversion factors) and from the base unit

Convert 6.32 µm to km Insert the values for 1 µm and 1 km

Convert 6.32 µm to km Cancel the units and do the math