Transcript Scientific Notation

Math Techniques
for
AP Physics
Scientific Notation
Mt. Everest -- 8845 m or
8.845 x 103 m
Flu Virus -- 0.00000023 m
or 2.3 x 10-7 m
A valuable way to express large and small numbers
A useful way to communicate the number of
significant figures in a numerical value
Rules for
Scientific Notation
• Decimal is moved so that one significant digit
precedes it
• Numbers are expressed as a value multiplied
by a power of 10
1230 
23405 
Rules for
Scientific Notation
• When the decimal is moved to the right, the
exponent is negative. When the decimal is
moved left, the exponent is positive.
8463 
0.00543 
0.00000054020 
Metric System
Widely used system of measurement because of
its ease of use
Base units are expressed with prefixes
representing various powers of ten
SI (Systeme International) Units
• the internationally agreed upon standard units
for the metric system
• Base SI units are:
Kilogram – mass
Meter – length
Second – time
Ampere – electric current
Other metric units derived from base units:
2
Newton -- kg x m/s
2 2
Joule -- kg x m /s
2
3
Volt -- kg x m /(A x s )
2
Tesla -- kg/(A x s )
Converting metric to metric:
250 cm = __________ m
45 kg = ___________ g
(force)
(energy)
(electric potential)
(magnetic induction)
Metric Prefixes
Unit Conversion
To change a measured value from one unit to
another, you need a conversion factor.
21.5 inches = _______ cm
1 inch = 2.54 cm
Think of that factor as a fraction. The conversion
factor will be set up so that the original units cancel
out to give you the new units
The 14 tallest peaks in the world are
referred to as “eight-thousanders,” meaning
the summits are 8000. m above sea level.
What is the elevation, in feet, of an elevation
of 8000. m?
m  cm  inches  feet
A silicon chip has an area of 1.25 square
inches. Express this area in square
centimeters.
1 in = 2.54 cm
2
1 in = ______ cm
2
Where the posted speed limit is 55 miles
per hour, what is the speed in meters per
second?
mi/hr  mi/s  ft/s  in/s  cm/s  m/s