distances in optics. This is the unit MOST people in
AP forget to convert)
x 10
-2
c
Milli-
( Used sometimes to express small
distances)
x 10
-3
m
Micro-
( Used mostly in electronics to express the
value of a charge or capacitor)
x 10
-6
μ
Nano
( Used to express the distance between
wave crests when dealing with light and the
electromagnetic spectrum)
x 10
-9
n
Tip:
Use your constant sheet when you forget a prefix value

Example
If a capacitor is labeled 2.5mF(microFarads),
how would it be labeled in just Farads?
The
FARAD
is the fundamental unit used when discussed capacitors!
2.5 x 10
-6
F
Notice that we just add the factor on the
end and use the root unit.
The radio station XL106.7 transmits at a
frequency of 106.7 x 10
6
Hertz. How would it
be written in MHz (MegaHertz)?
A
HERTZ
is the fundamental unit used when discussed radio frequency!
106.7 MHz
Notice we simply drop the factor and add
the prefix.

Dimensional Analysis
Suppose we want to convert 65 mph to ft/s or
m/s.
Dimensional Analysis is simply a technique you can use to convert from one unit
to another. The main thing you have to remember is that the
GIVEN UNIT MUST
CANCEL OUT.
hour
miles
65
sec
60
min
1
min
60
1
•
hour
mile
ft
1
5280
=
×
×
×
×
×
×
⇒
1
60
60
1
5280
1
1
65
s
ft
95
s
ft
95
ft
meter
281
.
3
1
=
×
×
⇒
281
.
3
1
1
95
s
m
/
29

#### You've reached the end of your free preview.

Want to read all 8 pages?

- Fall '11
- Burgeson
- Physics, Mass, Hertz, AP Physics, International System of Units, SI prefix, fundamental unit