Chapter 1 Chapter 1 MeasurementMeasurement

MeasurementMeasurement Is a determination of the Is a determination of the

amount of somethingamount of something Is defined as a Is defined as a comparisoncomparison to to

a a known standardknown standard–What does “5 feet tall” What does “5 feet tall”

mean????mean????– Do you have to know what Do you have to know what a a

footfoot is in order for this to make is in order for this to make sense?sense?

Measurements have two parts, a number value and a unit

Units and StandardsUnits and Standards What is a What is a standardstandard ??

1.) Historically things such as hands and 1.) Historically things such as hands and feet were used to make measurements, feet were used to make measurements, and other things were compared to that and other things were compared to that size.size.

2.) A 2.) A standardstandard is something that you is something that you compare other amounts to.compare other amounts to.

Two Measurement Two Measurement SystemsSystems English system-used for everyday English system-used for everyday

measurement in the US.measurement in the US.– Include units of miles, feet, Include units of miles, feet,

inches, pounds, pints, quarts, inches, pounds, pints, quarts, gallons, cups, and teaspoonsgallons, cups, and teaspoons

Metric SystemMetric System

MeasurementMeasurement In 1960 an International Committee In 1960 an International Committee

agreed to a system of standards to be agreed to a system of standards to be used by scientists worldwide.used by scientists worldwide.

Scientists use the metric system or SI Scientists use the metric system or SI for for le System Internationale d’Unitsle System Internationale d’Units

Makes sharing data easierMakes sharing data easier Goal for using metric system was to Goal for using metric system was to

have all units of measurement be have all units of measurement be relatedrelated

Metric SystemMetric System

Units include a Base unit and Units include a Base unit and prefixprefix– Base units include Liters, Base units include Liters,

meters, and gramsmeters, and grams– Prefixes multiply or divide the Prefixes multiply or divide the

base units base units by multiples 10by multiples 10

PrefixesPrefixesPrefix Symbol Meanin

gAs a numberkilo- k thousan

d1,000

mega-

M million 1,000,000

giga- G billion 1,000,000,000deci- d tenth 0.1

centi- c hundredth

0.01

milli- m thousandth 0.001

micro-

millionth 0.000 001

Conversion factors….Conversion factors….

1000 milli-units = 1 base unit1000 milli-units = 1 base unit 100 centi-units = 1 base unit100 centi-units = 1 base unit 10 deci- units = 1 base unit10 deci- units = 1 base unit 1000 base units = 1 kilo-unit1000 base units = 1 kilo-unit

1. 2 Time and Distance1. 2 Time and Distance Time is used in two waysTime is used in two ways– To indicate a particular moment To indicate a particular moment

in the past or the futurein the past or the future Tomorrow at 3:00Tomorrow at 3:00

– To indicate a quantity of time….To indicate a quantity of time…. 30 seconds 2 minutes, 15 seconds30 seconds 2 minutes, 15 seconds

Measuring Measuring Length/DistanceLength/Distance Use a ruler/taper Use a ruler/taper

measuremeasure Line up from zero not Line up from zero not

the end of the rulerthe end of the ruler Small divisions are Small divisions are

millimetersmillimeters

Micrometer Vernier Caliper

This reads 3.3

MassMass Weight is the force of gravity acting on Weight is the force of gravity acting on

an object, mass is the an object, mass is the amount of matter amount of matter in an objectin an object. (they are different things). (they are different things)

Metric unit of mass is the Metric unit of mass is the gramgram 1gram is defined as the mass of 1 cm1gram is defined as the mass of 1 cm33

of water at 4 ºC.of water at 4 ºC. 1 kg = 1 L of water1 kg = 1 L of water 1 kg = 2.2 lbs1 kg = 2.2 lbs 1 g = 1 small paper clip1 g = 1 small paper clip 1 mg = 10 grains of salt or 2 drops of 1 mg = 10 grains of salt or 2 drops of

water.water.

Measuring MassMeasuring Mass Use a triple beam balanceUse a triple beam balance First balance it at zero.First balance it at zero. Then put item onThen put item on Then move one weight at a timeThen move one weight at a time When balanced, add up the When balanced, add up the

weightsweights

VolumeVolume

Defined as the Defined as the space occupied space occupied by some object or substanceby some object or substance

Liter a common unit, cubic Liter a common unit, cubic meter (mmeter (m33) is SI unit 1 L about ) is SI unit 1 L about 1/4 of a gallon - a quart1/4 of a gallon - a quart

1 mL is about 20 drops of 1 mL is about 20 drops of water or 1 sugar cubewater or 1 sugar cube

1 ml = 1 cm1 ml = 1 cm33

Measuring Volume of a Measuring Volume of a LiquidLiquid

Use a Use a graduated graduated cylindercylinder..

The water will curve The water will curve in the cylinder.in the cylinder.

Hold it level with Hold it level with your eye.your eye.

Read the bottom of Read the bottom of the curve the curve (meniscus)(meniscus)

Measures in Measures in milliliters mL.milliliters mL.

Measuring Volume of a solid Measuring Volume of a solid ObjectObject Can be accomplished by using the Can be accomplished by using the

“displacement method”“displacement method”– Objects in water will displace, or Objects in water will displace, or

push aside, their volume in push aside, their volume in water.water.

1. Record initial volume

2. Record Final Volume

3. Subtract initial volume from final volume to get volume of object

Measuring Volume of Measuring Volume of Regular Solid ObjectRegular Solid Object You can calculate the volume of a You can calculate the volume of a

regular object such as a cube or regular object such as a cube or rectangular solid by using the rectangular solid by using the equation equation

Volume = Length X Width X Height

Volume calculator

DensityDensity Description of matter that is a Description of matter that is a comparison comparison

of mass and volumeof mass and volume Calculated using the equation Calculated using the equation

Density = Density = MassMass

VolumeVolume

Density of water = 1 g/cmDensity of water = 1 g/cm33 = 1000kg/m = 1000kg/m33

– If material density > water, it will sinkIf material density > water, it will sink– If material density < water, it will floatIf material density < water, it will float

TemperatureTemperature Measured with a thermometerMeasured with a thermometer Common metric units are either Common metric units are either

Celsius or KelvinCelsius or Kelvin Measure of the average kinetic Measure of the average kinetic

energy of molecules or atoms of a energy of molecules or atoms of a substance (faster ones have more substance (faster ones have more KE and are “hotter”)KE and are “hotter”)

Water freezes at 0Water freezes at 0°C, boils at °C, boils at 100°C100°C

Temperature ConversionsTemperature Conversions

TimeTime

Common base unit of Common base unit of seconds,seconds, but can be measured in but can be measured in hours/days/years/etc..hours/days/years/etc..

1 year = 365 days1 year = 365 days 1 day = 24 hours1 day = 24 hours 1 hour = 60 minutes1 hour = 60 minutes 1 minute = 60 seconds1 minute = 60 seconds

ForceForce Use a force gauge to measure, or Use a force gauge to measure, or

a a spring scalespring scale like we use in this like we use in this classclass

Measure in units of “Newtons”Measure in units of “Newtons”

Metric conversionsMetric conversions Changing the unitChanging the unit Does not change the size of the Does not change the size of the

measurementmeasurement If the unit gets bigger the number gets If the unit gets bigger the number gets

smallersmaller If the unit gets smaller the number If the unit gets smaller the number

gets biggergets bigger Math with multiples of 10Math with multiples of 10 We will We will cancel out unitscancel out units to make sure to make sure

we set the problem up rightwe set the problem up right

Metric conversionsMetric conversions ““A common race is the 5 K, which is A common race is the 5 K, which is

5 km. How many meters is this?”5 km. How many meters is this?” Given unit -kmGiven unit -km Unit wanted –mUnit wanted –m The unit gets smaller, so the number The unit gets smaller, so the number

must get biggermust get bigger 1000 m = 1 km1000 m = 1 km

Metric conversionsMetric conversions

Distance in m = 5 km

Distance in m = 5000 m

1000 m

1 km x

Metric conversionsMetric conversions The recommended daily The recommended daily

requirement of vitamin C is 500 requirement of vitamin C is 500 mg. How many grams is this?mg. How many grams is this?

mass in g = 500 mg

mass in g = 0.5 g

1 g

1000 mg

x

How many centimeters are there in

5.7 meters?

100 kilometers/hour is a 100 kilometers/hour is a typical speed limit in typical speed limit in Canada. What is this speed Canada. What is this speed equal to in meters/sec?equal to in meters/sec?