Length- the basic unit of length is the meter.

1
Scientific Measurement

• Length- the basic unit of length is the meter.
• Meter- SI unit of length - It is the
  distance between the doorknob and the floor.

2
Scientific Measurement

• Volume- is the amount of space that something
  occupies.
• Liter - SI unit for volume ....- A little more
  than a quart ... - Solid objects can have volumes
  in cubic centimeters

3
Scientific Measurement

• Mass- is the amount of matter an object contains.
• Kilogram- the basic SI unit for mass.
• About 2.25 pounds.
• A smaller unit is the gram.

4
The Metric System

• Easier to use because it is a decimal system
• Every conversion is by some power of 10.
• Much easier to use when doing calculations.

5
The Metric System

• A metric unit has two parts
• A prefix and a base unit.
• prefix tells you how many times to divide or
  multiply by 10.

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SI Base Units

• Length - meter - m
• Mass - gram - g
• Time - second - s
• Temperature- Kelvin (K) or ºCelsius (ºC)
• Volume - Liter - L

7
SI Prefixes

• kilo k 1000 times
• hecto h 100 times
• deca D 10 times
• kilometer - equals 1000 meters or about 0.6 miles

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SI Prefixes

• deci d 1/10
• centi c 1/100
• milli m 1/1000
• centimeter - 1/100 of a meter or less than half
  an inch

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Measuring Length

• Line up from zero not the end of the ruler
• Small numbered divisions are centimeters (parts
  are mm)

0
1
2
3
4
10
Measuring Volume
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• Use a graduated cylinder.
• Hold it level with your eye.
• Read the bottom of the curve.
• Measures in milliliters mL.
• A meniscus is the curvature of the surface of the
  water

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10
11
Mass vs Weight

• Weight is a measure of the pull of gravity and,
  mass is the amount of matter.
• The weight of an object can change, but an
  objects mass is constant.

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Triple Beam Balance Use

• Use a triple beam balance
• First zero the balance.
• Then place object on pan.
• Then move largest weight first, until pointer
  tips to right and move back one notch.

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Triple Beam Balance Use

• Move next smallest weight, until pointer tips to
  right and move back one notch.
• Move smallest weight, until pointer is at
  mid-position.
• When balanced, add up the weights.

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Triple Beam Balance
0
1
2
3
4
5
6
7
8
9
10
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Electronic Balance Use

• Press on button to turn on.
• If balance in not on zero, press zero button.
• Place object on pan and, record mass in grams.
• Turn balance off at end of lab period.

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Date 01/19/11Instructional Objective1.Review
the metric system2.Learn how to convert the
metric system Review Questionsa.) 68.882 kg
_______________________cgb.) 428 mm
________________________dkmOther
InstructionsMove to the lab station and Work on
your Density lab.HomeworkDo the SI unit work
sheet.
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Metric Conversions

• how far you have to move on this chart, tells you
  how far, and which direction to move the decimal
  place.

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Metric Conversions

• Change 5.6 mg to kilograms.
• starts at milli position and move six places to
  the left.

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Metric Conversions

• move the decimal point six places to the left
  0.0000056
• 5.6 mg 0.0000056 kg

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Metric Conversions

• Change 5.6 m to millimeters
• starts at the base unit position and move three
  places to the right.

21
Metric Conversions

• move the decimal point three to the right 5600.
• 5.5 m 5600. mm

22
Metric Conversions

• convert 25 mg to grams
• convert 0.45 km to mm
• convert 35 mL to liters

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Scientific Measurement

• Density- tells you how much matter is packed into
  a given volume.
• Calculated by dividing mass by volume ( D M )
  . V

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Density Problem

• Calculate the density of an object with a mass of
  25 g a volume of 5.0 mL.
• .D M 25 g 5.0 g/mL . V
  5.0mL

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Example problems 10 km _____ dm 0.1 hm _____
m 1cm _____ hm 0.01 m _____ mm 100 dg _____
dag 10 hg _____ kg 0.1 mg _____ dg 0.001 cg
_____ mg 1 kg _____ g 0.01 dag _____ cg
Now lets see how well you can perform
some conversions!!
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The centigrade (Celsius) scale

• temperature (K) temperature (C) 273.15
• the melting point of water is 0C 273.15 K
• the boiling point of water is 100C 373.15 K

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reading a graduated cylinder
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The boiling point

• is the temperature at which the vapor pressure
  of a liquid is one atmosphere.
• Units - K (Kelvin)

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The Fahrenheit scale

• the melting point of water 32F
• the boiling point 212F.

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The SI unit of temperature is Kelvin (K).
Notice that there is no degree sign used with the
abbreviation. To covert from Celsius to Kelvin
temperatures C--gt K 273 K--gt C -
273 Celsius Kelvin Fahrenheit Freezing
0 273 32 Boiling 100 373
212
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Dervied units are combinations of SI
units. Volume amount of space occupied by an
object. VolumeLength X Width X Height V l X w
X h This is used to calculate the volume of a
cube and combines three length
measurements together. Density the mass per
unit volume of a material. DensityMass/Volume D
m/V This is a combination of units of mass and
volume.
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Density of the regular object

• Mass- find the mass of the object
• using a balance
• Volume- To find the volume by measuring the
  length, width, and height.
• Then calculate densitymass/volume

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Density of the irregular object

• Mass- find the mass of the unknown
• using a balance
• Volume- To find the volume, first measure the
  water that can immerse the irregular object in a
  graduated Cylinder.
• Then dropped the object in the cylinder and note
  the displacement measurement.
• Density mass/volume.