Metric System Scientific Measurements copyright cmassengale

Metric SystemMetric System

Scientific Scientific MeasurementsMeasurements

copyright cmassengale

Metric SystemMetric System Developed by the French in the late Developed by the French in the late

1700’s.1700’s. Based on powers of ten, so it is very easy Based on powers of ten, so it is very easy

to use.to use. Used by almost every country in the world, Used by almost every country in the world,

with the notable exception of the USA.with the notable exception of the USA. Especially used by scientists.Especially used by scientists. Abbreviated SI, which is French for Abbreviated SI, which is French for

Systeme International.Systeme International.


Metric PrefixesMetric Prefixes

Regardless of the unit, the entire Regardless of the unit, the entire metric system uses the same prefixes.metric system uses the same prefixes.

Common prefixes are:Common prefixes are:

kilo = 1000kilo = 1000

centi = 1/100centi = 1/100thth

milli = 1/1000milli = 1/1000thth

1 meter = 100 centimeters= 1000 1 meter = 100 centimeters= 1000 millimetersmillimeters


LengthLength

Length is the Length is the distance distance between two between two points.points.

The SI base unit The SI base unit for length is the for length is the metermeter..

We use rulers or We use rulers or meter sticks to meter sticks to find the length of find the length of objects.objects.


MassMass Mass is the amount of matter that makes Mass is the amount of matter that makes

up an object.up an object. A golf ball and a ping pong ball are the A golf ball and a ping pong ball are the

same size, but the golf ball has a lot more same size, but the golf ball has a lot more matter in it. So the golf ball will have matter in it. So the golf ball will have more mass.more mass.

The SI unit for mass is the The SI unit for mass is the gramgram.. A paper clip has a mass of about one A paper clip has a mass of about one

gram.gram. The mass of an object will not change The mass of an object will not change

unless we add or subtract matter from it.unless we add or subtract matter from it.


Measuring MassMeasuring Mass We will use a We will use a triple beam balancetriple beam balance

scale to measure mass.scale to measure mass. Gravity pulls equally on both sides of Gravity pulls equally on both sides of

a balance scale, so you will get the a balance scale, so you will get the same mass no matter what planet you same mass no matter what planet you are on.are on.


WeightWeight

Weight is a measure of the force of Weight is a measure of the force of gravity on an objectgravity on an object..

Your weight can change depending on Your weight can change depending on the force of gravity. The gravity will the force of gravity. The gravity will change depending on the planet you change depending on the planet you are on.are on.

The SI unit for weight is the The SI unit for weight is the NewtonNewton (N).(N).

The English unit for weight is the The English unit for weight is the pound.pound.


GravityGravity

Gravity is the force of attractionGravity is the force of attraction between between any two objects with mass.any two objects with mass.

The force depends on two things:The force depends on two things: more distance = less gravity = less weightmore distance = less gravity = less weight less distance = more gravity = more less distance = more gravity = more

weightweight more massmore mass = = more gravitymore gravity = more weight = more weight less massless mass = = less gravityless gravity = less weight = less weight


VolumeVolume Volume is the amount Volume is the amount

of space contained in of space contained in an object.an object.

We can find the We can find the volume of box shapes volume of box shapes by the formula by the formula Volume = length x Volume = length x width x heightwidth x height

In this case the units In this case the units would be would be cubic cubic centimeters (cmcentimeters (cm33).).

So a box 2 cm x 3 cm So a box 2 cm x 3 cm x 5cm would have a x 5cm would have a volume of 30 cmvolume of 30 cm33

V = L x W x HV = L x W x Hcopyright cmassengale

Base UnitsBase Units

The base unit The base unit for volume is for volume is the the LiterLiter..

We measure We measure volume with a volume with a graduated graduated cylindercylinder..


Graduated CylindersGraduated Cylinders

Liquids form Liquids form curved, upper curved, upper surfaces when surfaces when poured into poured into graduated cylindersgraduated cylinders

To correctly read To correctly read the volume, read the volume, read the bottom of the the bottom of the curve called the curve called the meniscusmeniscus


Water DisplacementWater Displacement

We can use We can use water water displacementdisplacement to find to find the volume of objects the volume of objects that are not boxed that are not boxed shaped.shaped.

We can put water in a We can put water in a graduated cylinder. If graduated cylinder. If a rock causes the level a rock causes the level to rise from 7 to 9 ml, to rise from 7 to 9 ml, the the rock must have the the rock must have a volume of 2-mL.a volume of 2-mL.


DensityDensity Density is the amount of matterDensity is the amount of matter

(mass) (mass) compared to the amount of compared to the amount of spacespace (volume) the object occupies. (volume) the object occupies.

We will measure mass in grams and We will measure mass in grams and volume in ml or cmvolume in ml or cm33


Density FormulaDensity Formula Density is mass divided by volume.Density is mass divided by volume. Density = mass/volumeDensity = mass/volume Remember, all fractions are Remember, all fractions are

division problems. division problems. Since the unit for mass is grams, Since the unit for mass is grams,

and the unit for volume is ml or and the unit for volume is ml or cmcm33, then the , then the unit for density is unit for density is g/ml, or g/ cmg/ml, or g/ cm33


Floating and SinkingFloating and Sinking Less dense Less dense

materials will float materials will float on top of more on top of more dense materials.dense materials.

Objects with a Objects with a density of less than density of less than 1-g/mL will float on 1-g/mL will float on top of water.top of water.

Objects with a Objects with a density greater than density greater than 1 g/mL will sink in 1 g/mL will sink in water.water.


Neutral BuoyancyNeutral Buoyancy

Objects with a Objects with a density equal to the density equal to the density of water will density of water will float in mid water, at float in mid water, at what ever level you what ever level you place the object.place the object.

Fish and submarines Fish and submarines control their depth control their depth by changing their by changing their density.density.


Objects that Sink!Objects that Sink!

Objects with Objects with a density a density greater than greater than 1 g/mL will 1 g/mL will sink in sink in water.water.


Comparing DensitiesComparing Densities

•Where is Where is the most the most dense dense object?object?

•Where is Where is the least the least dense dense object?object?


TemperatureTemperature

The base unit for temperature is The base unit for temperature is CelsiusCelsius. .

C=(F-32)x5/9C=(F-32)x5/9 C=(93-32)x5/9C=(93-32)x5/9

33 degrees Celsius33 degrees Celsius


TimeTime

The base unit for time is The base unit for time is seconds.seconds.


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Metric System Scientific Measurements copyright cmassengale