Measurement-A Common Language

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Measurement-A Common Language
EQ How do I define mass, weight and density?
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Mass

• The measure of the amount of matter an object
  contains
• Matter The material that all objects and
  substances are made up of
• Anything that has mass and takes up space is
  matter

EQ How do I define mass, weight and density?
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Units of Mass

• International System of Units
• Abbreviated as SI after its French name Systeme
  International
• The basic unit of mass in the SI system is the
  kilogram.

EQ How do I define mass, weight and density?
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Milligrams

• Used to measure smaller objects such as a paper
  clip

EQ How do I define mass, weight and density?
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Conversions
1 kg 1,000 g
1 g 1,000 mg
EQ How do I define mass, weight and density?
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Mass

• Measuring Mass

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How does a triple-beam balance work?

• A triple-beam balance works by comparing the mass
  of the object you are measuring to a known mass
• When you use a triple-beam balance, you
• Place the object on the pan
• Shift the riders on the beams until they balance
  the mass of the object
• Start with the large rider (increments of 100)
• Next, the medium sized rider (increments of 10)
• Lastly, the small rider (increments of 1)

EQ How do I define mass, weight and density?
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Mass

• The Difference Between Mass and Weight

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Weight

• The measure of the force of gravity acting on an
  object

EQ How do I define mass, weight and density?
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How would your weight differ if you were to
travel to the moon?

• If you were to travel to the moon your weight
  would be less.
• Your weight would be lesser because the force of
  gravity is less.
• Weight is a factor of the force of gravity

EQ How do I define mass, weight and density?
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Why would your mass stay constant if you were to
travel to the moon?

• Your mass would stay the same if you were to
  travel to the moon because mass is the amount of
  matter that an object contains
• Since you are still made up of the same amount of
  stuff, your mass would not change

EQ How do I define mass, weight and density?
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Why use the mass of an object instead of its
weight?

• mass does not change when the force of gravity
  does

EQ How do I define mass, weight and density?
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Volume

• The amount of space an object takes up

EQ How do I define mass, weight and density?
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• Liter (L) used to measure the volume of a
  liquid.
• Milliliter (mL) - To measure the volume of
  smaller liquids

EQ How do I define mass, weight and density?
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The instrument used to measure the volume of
liquids is called the

• Graduated cylinder.

EQ How do I define mass, weight and density?
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This instrument has markings that are in
increments of

• 1 milliliter (mL)

EQ How do I define mass, weight and density?
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Meniscus

• The curve in the top surface of water in the
  graduated cylinder

EQ How do I define mass, weight and density?
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What is the proper way to read a meniscus?

• Read the milliliter marking at the bottom of the
  curve

EQ How do I define mass, weight and density?
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Volume of a solid object

• To measure a solid objects that are regular
  shaped, a formula for volume can be applied
• To measure a rectangular object such as a
  shoebox, multiply the objects length, width, and
  height

EQ How do I define mass, weight and density?
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The SI unit known for measuring solids with a
larger volume is known as the

• Cubic meter (m³) - The SI unit used to measure
  solids with a larger volume

EQ How do I define mass, weight and density?
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Common Conversions For Volume Common Conversions For Volume Common Conversions For Volume
1 L 1,000 mL
1 L 1,000 cm³
1 mL 1 cm³
EQ How do I define mass, weight and density?
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The formula for calculating the volume of a
rectangular object is

• Volume Length x Width x Height

EQ How do I define mass, weight and density?
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Why is the unit cm³ used when calculating the
volume of a rectangular object?

• When multiplying the objects length, width and
  height, the cm units are also multiplied
• cm x cm x cm cm³

EQ How do I define mass, weight and density?
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Suppose a cereal box is 10 centimeters long, 4
centimeters wide, and 20 centimeters high. What
would be the volume of the box?

• Volume Length x Width x Height
• Volume 10 cm x 4 cm x 20 cm
• Volume 800 cm³

EQ How do I define mass, weight and density?
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Volume of an Irregular Solid

• Water displacement method
• To measure the volume of an irregular solid,
  immerse the object in water, and measure how much
  the water level rises

EQ How do I define mass, weight and density?
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Steps for the water displacement method

• Record the volume of water in the graduated
  cylinder
• Carefully place the irregular solid into the
  water. Record the volume of the water plus the
  object
• Subtract the volume of the water alone from the
  volume of the water plus the object

EQ How do I define mass, weight and density?
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Density

• The measure of how much mass is contained in a
  given volume
• The density of a substance is the same for all
  samples of that substance.

EQ How do I define mass, weight and density?
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The formula of density is

• Density Mass / Volume

EQ How do I define mass, weight and density?
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Why is density expressed as a combination of two
different units?

• Because density is actually made up of two other
  measurements mass and volume an objects
  density is expressed as a combination of two units

EQ How do I define mass, weight and density?
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Two Common Units For Density

• Grams per cubic centimeter (g/cm³)
• Grams per milliliter (g/mL)

EQ How do I define mass, weight and density?
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Math Practice What is the density of a wood
block with a volume of 125 cm³ and a mass of 57
g?

• Density mass / volume
• Density 57 g / 125 cm³
• Density 0.46 g/ cm³

EQ How do I define mass, weight and density?
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Math Practice What is the density of a liquid
with a mass of 45 g and a volume of 48 mL?

• Density mass / volume
• Density 45 g / 48 mL
• Density 0.94 g/mL

EQ How do I define mass, weight and density?
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An object floats if it is less dense than a
surrounding liquid.
Densities of Some Common Substances Densities of Some Common Substances
Substance Density (g/cm³)
Air 0.001
Ice 0.9
Water 1.0
Aluminum 2.7
Gold 19.3
EQ How do I define mass, weight and density?
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How could you use density to determine whether a
bar of metal is pure gold?
Densities of Some Common Substances Densities of Some Common Substances
Substance Density (g/cm³)
Air 0.001
Ice 0.9
Water 1.0
Aluminum 2.7
Gold 19.3

• If the bar of gold has a density that is greater
  than or less than 19.3 g/cm³, then the sample is
  not pure gold.

EQ How do I define mass, weight and density?
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Will an object with a density of 0.7 g/cm³ float
or sink in water?

• An object that has a density of 0.7 g/cm³ will
  float in water (1 g/cm³) because it is less dense
  than water

EQ How do I define mass, weight and density?