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DIFFICULTY OF THE IMPERIAL UNITS?
One inch is usually divided into 8, 10 or 16 parts:
DIFFICULTY OF THE IMPERIAL UNITS
This particular ruler has 16 divisions
One inch is usually divided into 8, 10 or 16 parts:
DIFFICULTY OF THE IMPERIAL UNITS
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?
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?
Videoclip
1.3 Relating SI and Imperial Units
Copyright © 2010 Ryan P. Murphy
Copyright © 2010 Ryan P. Murphy
Gallon
Mph (Miles per hour)
Pounds
Inches Yards Fahrenheit
I will show you these 6 pictures showing you their metric values.
One gallon of milk = 3.78 liters of milk
65 mph = 104 km/h
Copyright © 2010 Ryan P. MurphyCopyright © 2010 Ryan P. Murphy
Double Quarter Pounder(0.5 pound) = 0.226 kg
48 inches tall = 1.22 meters tall
Copyright © 2010 Ryan P. MurphyCopyright © 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
The simplicity of the Metric System?
Copyright © 2010 Ryan P. Murphy
For example:LENGTH:meter
MASS: gram
VOLUME: liter
Only one unit of measurement for each quantity
You can measure the very small and the very large with the same unit
Copyright © 2010 Ryan P. Murphy
meter
The measurements below are all the same.
Copyright © 2010 Ryan P. Murphy
“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
The simplicity of the Metric System?
Copyright © 2010 Ryan P. Murphy
SIFor example:LENGTH:meter
MASS: gram
VOLUME: literOnly one unit of measurement
for each quantity 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)…
Imperial
Dimensional Analysis and Conversion factors
Any quantity we measure,(length, mass, volume…) consists of a number and unit
If we are given a quantity in one type of unit, and we want another type of unit :
22.2 m
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 #1Convert 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
EXAMPLE #1Convert 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
Convert 21.5 inches to cm!
Step 2: Choose a conversion factor which will allow you to cancel units of a given
quantity (inches in our case)
Convert 21.5 inches to cm!
𝟏 𝒊𝒏𝒄𝒉𝟐 .𝟓𝟒𝒄𝒎
21.5 inches x
𝟐 .𝟓𝟒𝒄𝒎𝟏 𝒊𝒏𝒄𝒉
21.5 inches x
NO!
YES!
Step 3: Multiply, cancel and check the units
EXAMPLE #1Convert 21.5 inches to cm!
1 step metric conversion
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
HOMEWORKOPages: 22 – 23
OProblems: 4 – 14 (all even)
Convert 6.32 µm to km1. Convert to a base
unit (need 2 conversion factors) and from the base unit
Convert 6.32 µm to km3. Insert the values for
1 µm and 1 km
Convert 6.32 µm to km4. Cancel the units and
do the math