Measurement: Tools and Units

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Measurement Tools and Units
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Length

• Unit meter (m)
• Also Common km, cm, mm
• Tool Meter Stick, Ruler
• 1 meter 100 cm 1000 mm

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To Find the Length of an object

• Determine what scale the measurement is in.
• Line up one end of the object with zero (be
  careful here!).
• Read the mark where the other end of the object
  is. Estimate between marks.

cm
1
2
4
3
5
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Mass

• Unit gram (g)
• Also Common kg, mg
• Tool Triple-Beam Balance

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To Find the Mass of an Object

• 1 Zero the Balance
• Make sure the Pan is clean. Move the sliders to
  zero and make sure the pointer lines up with the
  zero line.
• 2 Place the Object on the Pan
• 3 Move the Sliders until the Pointer lines up
  with the Zero Line
• Start with 100s slider, then 10s, then 1s.
• 4 Add the Sliders together

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Volume

• Unit Liter (L)
• Also Common mL, cm3, cc
• Tool Graduated Cylinder
• Meniscus the curve that the liquid makes inside
  the cylinder
• Read the bottom of the curve!

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Volume by Displacement

• Used for finding the volume of irregularly shaped
  objects (object cannot float in water)
• Record the beginning water level.
• Carefully slide the object into the graduated
  cylinder.
• Record the new water level.
• The change in water level is equal to the volume
  of the object.

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Temperature

• Unit Degrees Celsius(C)
• Also Common Kelvin (K)
• Tool Thermometer
• Usually, the thermometer is filled with red
  alcohol that will expand or contract depending on
  the kinetic energy of the molecules.

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Density

• Unit grams per cubic centimeter (g/cm3) or grams
  per milliliter(g/mL)
• Calculated, not measured!
• d m/v
• Density equals mass divided by volume

m
d
v