# measurement

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```					                    measurement
   -a way to describe the world with numbers
   Answers questions: how much? How long? How far?
   Describe the amount; cost; distance; volume; mass; how fast; age
   Information described with numbers

Chapter 2 Vocabulary/Notes
Estimation
• Helps you make a rough measurement of
an object by guessing
• Based on experience
• Useful when you are in a hurry and exact
data is NOT required
• Improve with experience, practice, and
understanding

Chapter 2 Vocabulary/Notes
Using Estimation

• You can compare an object whose length
you don’t know to familiar objects
• Often use the word “about”
• Also used to check that an answer is
reasonable
• 1 m = about height of a door knob above the
floor
• 1 mm = about the thickness of a dime

Chapter 2 Vocabulary/Notes
Precision
• Describes how carefully you make your
measurement
• The tool used determines the precision of
the measurement
• The more improved the tool the more
précised the measurement
• Can be reproduced or copied

Chapter 2 Vocabulary/Notes
accuracy
• Compares a measurement to the real
value
• The more accurate the measure, the
closer it is to the true value

Chapter 2 Vocabulary/Notes
Steps in Rounding
• Not all measurements must be measured with great
precision

• 1. Look at the digit to the right of the place being
rounded
– The digit remains the same if the digit to the right is 0, 1, 2, 3, or 4
– Round up if the digit to the right is 5, 6, 7, 8, or 9

2. The remaining digits to the right of the rounding place
are eliminated from the rounded answer if it is a
decimal

Chapter 2 Vocabulary/Notes
SI
•   Means International System of Units
•   Established in 1960
•   General system for measurement
•   To avoid confusion, scientists use this common
language
•   Worldwide standard of physical measurement for
industry, science, and commerce
•   Uses units such as meters, cubic meter, grams, and
Kelvin
•   Uses multiples of 10
•   To convert between units you multiply or divide by
powers of 10

Chapter 2 Vocabulary/Notes
length
• Distance between two points
• Use the meter unit to measure

Chapter 2 Vocabulary/Notes
volume
• Amount of space an object occupies
• Cubic meter (cm3) is used
• Formula: Volume=length x width x height
or           V = l x w x h or V = (l)(w)(h)
• Liquid volume is measured using liter
• 1 cm3 = 1 mm of water

Chapter 2 Vocabulary/Notes
mass
• Measures the amount of matter in an object
• Uses kilogram unit
• 1 L of water = 1 kg
• Use a pan balance to measure
• Pan balance compares an object to a known mass; it is
balanced when the masses on both sides are equal
• Depends on the amount of matter in an object
• NEVER changes

• Mass and weight ARE NOT the same

Chapter 2 Vocabulary/Notes
Weight
• Measurement of force
• Depends on gravity
• Can change depending on where the
object is located
• Spring scale measures weight; the reading
on the scale depends on the force pulling
the spring

Chapter 2 Vocabulary/Notes
temperature
•   Measures how hot or cold an object is
•   In SI it is measured with the Kelvin (K) scale
•   Measured also in Fahrenheit or Celsius
•   273 K = 0°C = 32°F (freezing point of water)
•   373 K = 100°C = 212°F (boiling point of water)
•   Zero Kelvin is the coldest temperature possible
in nature

Chapter 2 Vocabulary/Notes
Time
• interval between two events
• Measured in seconds (s) or hours (h)

Chapter 2 Vocabulary/Notes
rates
• A ratio of two measurements with different
units
• Example: speed-distance traveled in a
given time
• Measured in kilometers per hour (km/h)
• Are combinations of units
Examples: grains/liter; °C/hour

Chapter 2 Vocabulary/Notes
photographs
• Shows an object exactly as it is
• Movie show can be slowed down or
speeded up

Chapter 2 Vocabulary/Notes
drawings
• Can show important things and leave out
unimportant details
• Illustrations
• Can show things we can’t photograph
• Can show hidden things
• sketches

Chapter 2 Vocabulary/Notes
Tables
• Organized way to collect and display data
• Displays info in rows and columns so it’s
easier to understand

Chapter 2 Vocabulary/Notes
graphs
• Show the relationships between the data
• Used to collect, organize and summarize
data in a visual way
• Can display one set of data or more
• Three common types:
-line graphs
-bar graphs
-circle graphs
Chapter 2 Vocabulary/Notes
Line graph
• Has two variable (something that can change or
vary)
• Used to show the relationship between
two variables
• Both variables must be numbers
• Has a vertical axis and a horizontal axis
(bottom line)

Chapter 2 Vocabulary/Notes
Bar Graph
• Uses bars to show the relationships
between variables
• One variable MUST be a number; the
other variable is divided into parts

Chapter 2 Vocabulary/Notes
Circle Graph
•   Shows the parts of a whole
•   The circle represents the whole
•   Sections represents the parts
•   All the sections together equal 100 percent

Chapter 2 Vocabulary/Notes
• The way you mark the scale on a graph
can create the wrong impression
• A broken scale (on the vertical axis) is
used for small but significant changes

Chapter 2 Vocabulary/Notes

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