difficulty of the imperial units?. one inch is usually divided into 8, 10 or 16 parts: difficulty of...

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

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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.

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POWERS OF TEN HAVE PREFIXES

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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

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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