Download Measurement - Laurel County Schools

Using Scientific Notation
Scientific Notation is a way of expressing
a value as the product of a number
between 1 and 10 and a power of 10.
 Scientific Notation makes very large or
very small numbers easier to work with.


Example: The number 300,000,000 written in
scientific notation is 3.0x108. The exponent, 8,
tells you that the decimal point is really 8 places
to the right of the 3.

Example: The number 0.00086 written in
scientific notation is 8.6x10-4. The negative
exponent, -4, tell you that the decimal point is
really 4 places to the left of the 8.6.


When multiplying numbers written in
scientific notation, you multiply the numbers
that appear before the multiplication signs
and add the exponents.
When dividing numbers written in scientific
notation, you divide the numbers that appears
before the exponential terms and subtract the
exponents.


Example: 3.0x108 x 5.0x102 = 15x1010 =
1.5x1011
Example: 1.5x1011 = 1.5x 1011-8 = 0.5x103
=5.0x102
3.0x108
3.0
International System of Units
 SI is built upon seven metric units, known
as Base Units.

› Example: The base unit for length(L) is the
meter (m).

Additional SI units, called Derived Units,
are from combinations of base units.
› Example: The derived unit for volume (V) is
cubic meters (m3).
Quantity
Unit
Symbol
Length
Meter
M
Mass
Kilogram
Kg
Temperature
Kelvin
K
Time
Second
S
Amount of substance
Mole
Mol
Electric current
Ampere
A
Luminous intensity
Candela
cd
Quantity
Unit
Symbol
Area
Square meter
M2
Volume
Cubic meter
M3
Density
Kilograms per cubic
meter
Kg/m3
Pressure
Pascal (kg/mxs2)
Pa
Energy
Joule (kgxm2/s2)
J
Frequency
Hertz (1/s)
Hz
Electric Charge
Coulomb (Axs)
C
Prefix
Symbol
Meaning
Multiply Unit by
Giga-
G
Billion
1,000,000,000
Mega-
M
Million
1,000,000
Kilo-
k
Thousand
1,000
Deci-
d
Tenth
0.1
Centi-
c
Hundreth
0.01
Milli-
m
Thousandth
0.001
Micro-
µ
Millionth
0.000001
Nano-
n
Billionth
0.000000001

A conversion factor is a ratio of
equivalent measurements that is used to
convert a quantity expressed in one unit
to another unit.

Example: Convert the height of Mt.
Everest, 8848 meters, into kilometers. kilo=1000
8848m X 1km = 8.848km
1000m
Precision is a gauge of how exact a
measurement is.
 Precision of a calculated answer is
limited by the least precise measurement
used in the calculation.
 Accuracy is the closeness of a
measurement to the actual value of
what is being measured.


Significant figures are all the digits that
are known is a measurement, plus the
last digit that is estimated.
› Example: On an analog clock it may take
you 5 minutes to eat a sandwich. On a
digital clock it may take you 5.25 minutes to
eat a sandwich. The time recorded as 5.25
minutes has three significant figures. The time
recorded as 5 minutes has one significant
figure. The fewer the significant figures, the
less precise the measurement.
Measuring Temperature
 A thermometer is an instrument that measures
temperature, or how hot an object is.
 The two temperature scales that you are
probably most familiar with are the Fahrenheit
scale and the Celsius scale.
 Fahrenheit: water freezes at 32 degrees
 Celsius: water freezes at 0 degrees
 Conversion:
 ºC = 5 (ºF – 32.0º)
9
or ºF = 9 (ºC) +32.0º
5

SI unit for temperature is kelvin (K).

Conversion:
K = ºC + 273

Textbook:
› Section 1.3 Assessment (page 20)
› Questions 1 – 6

Workbook:
› Section 1.3 Measurement (pages 7-8)