Going MetricMetric Measurement Introduction

History of Measurements

In ancient times, as trade developed between cities and nations, units of measure were developed to measure the size of transactions and purchases.

History continued

During the Renaissance, as scientist began to develop ideas of physics and chemistry, they needed standard units of measure to communicate their ideas and theories effectively.

Beginnings of metric system

In March 1791, in Sevres, France, the French Academy of Science proposed a standardized system that would be easy to use.

This system is now called the SI system

French Le Systéme International d’Unités

LengthThey based their units of length on a fractional system of the distance between the equator and the North Pole.

The system’s basic unit of length measure was called the meter

Meter in Greek (metron) means measure

Today, length of a meter is defined as the distance light travels in a small fraction of a second

Origins of Common Metric Measurements

5 city blocks = 1 kilometer

Height of a 1st grader

1 meter

Width of your pinky

finger1 centimeter

Width of pencil lead

1 millimeter

Mass

1 kilogram is defined by a specific lump of platinum that is kept in Paris in controlled conditions to keep it from any chemical changes

You may wonder why the based unit for mass is the kilogram and not the gram

A gram is quite a small unit of mass

Volume

The liter is the base unit for volume

One milliliter (mL) is the volume of one gram (g) of water or one cubic centimeter of water

TemperatureThe base unit for the measure of temperature is one degree celsius (or centigrade if you’re old enough to remember this)

0° celsius = freezing (water)

100° celsius = boiling (water)

37° celsius = normal human body temperature

Modern DayMost of the world uses the metric system in daily life

You might be surprised to note that the US sanctioned the use of the metric system in 1884, but people have clung on to the use of the English or Imperial system

Since 1992, US government agencies have been required to use the metric system in business transactions

Meter (m)

Liter (L)

Kilogram (kg)

Metric Abbreviations - Base Units

Units of the metric system

Measurement Type

Base unit Unit Symbol

Mass kilogram kg

Volume liter l

Length/distance meter m

Temperature degree celsius ˚c

Metric Step Ladder

How to use Metric Step Ladder

1st - determine your starting point

2nd - count the “jumps” to your ending point

3rd - move the decimal point the same number of jumps

Metric Units - Length/Distance

1 Kilometer (km) = 1000 meters 3 jumps

1 Meter = 100 Centimeters (cm) 2 jumps

1 Meter = 1000 Millimeters (mm) 3 jumps

Measuring MassMass refers to the amount of matter in an object

1 kilogram = 1000 grams 3 jumps

1 gram = 1000 milligrams 3 jumps

We will be using a triple-beam-balance to measure mass

Interactive triple-beam-balance tutorial: http://www.ohaus.com/input/tutorials/tbb/tbbentry.swf

Measuring Volume

Volume is defined as the amount of space an object takes up

1 liter = 100 centimeters 2 jumps

1 mL (of water) = 1g = 1 cm3

measured: l ⨯ w ⨯ h

Measuring VolumeWe will be using graduated cylinders to find the volume of liquids

Measure at the bottom of the meniscus

Any ideas why?

To measure the volume of regular objects use: l ⨯ w ⨯ h