Density

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Density

• Tutorial created by
• Courtney Richardson

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What is Density?

• Density is how much space matter takes up
• Density is found by taking your mass divided by
  your volume
• Density is measured in grams/millimeters when
  involving solids or liquids, but if involving gas
  it is measured in grams/liters

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More about Density

• The density of water is 1.00g/ml
• If an object is less then 1.00g/ml then it will
  float, if it is more then it will sink

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Mass

• Mass is the amount of matter an object has
• Mass is almost always measured in grams when
  dealing with density
• Is usually measured with a balance when dealing
  with itself

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Volume

• Volume is the amount of space an object occupies
• Volume in a density problem involving solids and
  liquids is measured in millimeters
• On the other hand, in a problem that involves
  gas, volume is measured in liters

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An example

• You have 45g of a substance that occupies a
  volume of 7.36ml, what is the density?
• Remember DensityMass/volume
• The mass is 45g and the volume is 7.36ml
  next slide

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Continued

• So then take 45g and divide it by 7.36ml
• Your density will come out to 6.114130434782608695
  6521739130435g/ml
• You round that to the nearest hundredth and you
  get 6.11g/ml

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One more example

• This one is a little harder
• If you have 884g of mercury at a volume of 65ml,
  what is the density of the mercury?
• If you take 884g divided by 65ml you will get
  13.6g/ml

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Sink or Float?

• If the density of water is 1.00g/ml and an object
  had a density of .336g/ml, will it sink or float?
• It will sink because it is less that 1.00g/ml

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Question 1

• What is the density of a board in which the
  dimensions are 5.54cmx10.6cmx199cm and whose
  mass is 28.6g? (round to the nearest thousandth)

Answer
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Answer 1

• First you take the dimensions and multiply them
  to get your volume
• 5.54cmx10.6cmx199cm 11686.076cm3 or
  11686.076ml
• Then take your mass and divide it by your
  volume
• 28.6g/11686.076ml0.002447g/ml
• Density 0.002g/ml

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Question 2

• What is the density of a rectangular box with
  dimensions that are 8cmx6cmx5cm and a mass of
  500g? (round to the nearest hundredth)

Answer
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Answer 2

• First take the dimensions and find the volume
• 8cmx6cmx5cm240cm3 or 240ml
• Then take your mass and divide it by your
  volume 500g/240ml2.083g/ml
• Density 2.08g/ml