Transcript 150LECTURE2FOLWERCHAPER1 Lecture Notes Page

FOWLER CHAPTER 1
LECTURE 2 BASIC CONCEPTS
SCIENTIFIC NOTATION (powers of ten)
SEE TABLE 2-1, P33
10
ANY NUMBER CAN BE EXPRESSED AS BASE
x
EXPONENT
(CAN BE POSITIVE OR NEGATIVE)
+ OR -
OTHER BASES AND EXPONENTS
23
35 1258
ANY NUMBER RAISED TO THE ZEROTH POWER IS EQUAL TO ZERO
EXAMPLES: 10
10 0  1 20  1, 10  1, 10000  1
WRITE 1000 IN SCIENTIFIC NOTATION
1000  103  1.0 103
1000 WRITE AS 1 FOLLOWED BY 3 ZERO’S
ANY NUMBER >0 CAN BE EXPRESSED THIS WAY.
EXAMPLE: 1,237 CAN BE EXPRESSED AS
1.237X10³
COUNT THE NUMBER OF DECIMAL PLACES TO THE RIGHT OF THE FIRST DIGIT
THEN PLACE THE DECIMAL PT. AFTER THE FIRST DIGIT.
1.237
1.237 THE NUMBER OF DECIMAL PLACES TO THE RIGHT OF THE FIRST
DIGIT IS THE EXPONENT EXPRESSED AS THE POWER OF TEN, IN THIS CASE IT IS 3
1,237 =1.237X10³
FOR NEGATIVE EXPONENTS(ANY NUMBER <0) FOLLOW THE PROCEDURE
ON THE PRIOR SLIDE, BUT IN THE REVERSE DIRECTION.
EXAMPLES: 10‫־‬¹ =0.1
10‫־‬² =0.01
10‫־‬³ =0.001
HERE WE COUNT DECEMICAL PLACES TO THE LEFT INSTEAD OF THE RIGHT.
EXAMPLE: 10‫־‬³ =0.001
0.001= 10‫־‬³
COUNT 3 PLACE TO THE LEFT.
FROM OUR LAST EXAMPLE LET’S WRITE 0.001237 IN S. N.
COUNT FROM THE FIRST DIGIT TO THE LEFT.
.001237 -3 IS THE EXPONENT FOR THIS POWER OF TEN.
SO .001237= 1.237X10‫־‬³
1,237 CAN ASLO BE EXPRESSED AS
12.37X10²=1,237
.001237 CAN ASLO BE EXPRESSED AS
1.237X10‫ ־‬³= .001237
OR 123.7X10¹=1,237
OR 0.1237X10‫־‬²=
DEPENDING ON WERE THE DECIMAL PT. IS
PLACED, BOTH RESULTS GIVE THE
NUMBER.
DEPENDING ON WHERE THE DECIMAL PT. IS
PLACED, BOTH RESULTS GIVE THE NUMBER.
.001237
ENGINEERING NOTATION
IN THIS SYSTEM POWERS OF TEN ARE ALWAYS MULTIPIES OF 3
103 ,106 ,109
OR
…ETC.
10 3 ,10 6 ,10 9
EXAMPLE: EXPRESS 27000 IN S.N. AND E.N.
2.7 10 4
E.N. 27 103
S.N.
METRIC PREFIXES
TABLE 2-2, P. 35
(ENGINEERING NOTATION)
POWER OF TEN
ELECTRICAL UNITS AND SYMBOLS TABLE 2-3 P.37
QUANTITY
UNIT
SYMBOL
CURRENT
AMPERE(A)
I
VOLTAGE
VOLT(V)
V
RESISTANCE
OHM(Ω)
R
FREQUENCY
HERTZ(Hz)
f
CAPACITANCE
FARAD(F)
C
INDUCTANCE
HENERY(H)
L
POWER
WATTS(W)
P
EXAMPLES : USES OF ENGINEERING NOTATION (E.N.)
1,000,000Ω =
27,340Ω =
1 10 6 
= 1MΩ
2.734  10 4 
=27.34X10³Ω =27.43KΩ IN E.N.
OR .0274MΩ
OR O.OOO274GΩ
0.000546Ω =.546X10‫־‬³ Ω = .546mΩ =546uΩ =546000nΩ
QUICK MATH REVIEW
4 OPERATES IN ALL OF MATHEMATICS
ADDITION
SUBTRACTION
MULTIPICATION
DIVISION
DIVISION AND MULTIPICATION CAN BE DERIVATED
FROM ADDITION AND SUBTRACTION.
MULTIPICATION IS A SERIES OF REPEATED ADDITIONS
EXAMPLE: 2X4=8
OR 2+2+2+2=8
DIVISION IS A SERIES OF REPEATED SUBTRACTIONS
EXAMPLE:
84  2
82  6
62  4
42  2
SIMPLE ALGEBRA
ANY QUANTITY ON BOTH SIDES OF AN EQUATION ARE EQUAL.
EXAMPLES
EXAMPLES
ADDITION
SUBTRACTION
V+V=2V
V-V=0
2V-V=V
V=V
I=I
R=R
1+1=2
1-1=0
A+B=C
ANY QUANTITY CAN BE ADDED OR SUBTRACTED
TO BOTH SIDES OF ANY EQUATION.
GIVEN
A+B=C
SOLVE FOR A
SINCE -B=- B, ADD THIS TO BOTH SIDES OF THE EQUATION.
A+B-B=C-B
SINCE B-B=0
A+0=C-B
A=C-B
SOLVE FOR B
A+B=C
ADD –A TO BOTH SIDES.
A+B-A=C-A
B+A-A=C-A
B+0=C-A
B=C-A
LAWS OF EXPONENTS
V CAN ALSO BE EXPRESSED AS V¹, SO V=V¹
ANY QUANTITY DIVIDED BY ITSELF= 1
SINCE
1/V=1/V
V=V
V(1/V) =V(1/V)
V(1/V) =V(1/V)
1=1
1/V CAN BE WRITTEN AS V‫־‬¹
1/V=V‫־‬¹
OR
1/ V
X
 V X
V/V = 1
OR V¹/V¹ =V¹‫־‬¹ =Vº =1
EXAMPLE: V²/V =V²/V¹ = V²‫־‬¹ =V¹ =V
OR VxV/V = VxV/V =V
V /V  V
X
EXAMPLE:
Y
V /V  V
2
3
V / R 
V / R 
X
2
EXAMPLE:
OR
2 3
X Y
V
1
 1/ V
V X / RX
 V 2 / R2
V / R V / R  V 2 / R 2
V   V V  V V   V
2 2
OR
EXAMPLE:
4
V   V
2   4   16
X Y
2 2
XY
2
V X  V Y  V X Y
V V  V
2
3
23
V
5
V V  V V V V V  V
1
1
1
1
1
11111
V
5
SQUARE ROOTS
WE CAN RAISE A BASE NUMBER TO ANY POWER
8² =64
LETS REVERSE THIS PROCESS
FIND
64
IS DEFINED AS A RADIAL SIGN
2
INDEX
2
ANOTHER WAY OF SHOWING THE SAME THING
64  X
INDEX: HOW MANY TIMES WAS THIS NUMBER X MULTILED BY ITSELF TO
GET 64
8  8  64
 2 64  8
ANOTHER WAY TO EXPRESS THIS
 8  8
 8
2
64  64
3
8  2  2  2  2  2
1
1/ 2
1/ 2
3
3
3


2 1/ 2
3 1/ 3
 82 / 2  81  8
 23 / 3  21  2
3 8  2
V X /Y  Y V X
V  V 1/ 2
SYMBOL  MEANS IS DEFINED AS
OR 2 V  V 1/ 2
EXAMPLE:
2
V 2  (V 2 )1/ 2  V 2 / 2  V 1  V
OHM’S LAW
V I
V  RI
R IS A PROPORTIONIALITY CONSTANT
 V  RI
 V  RI
V  IR
THE PRODUCT IR CAN BE WRITTEN SEVERAL WAYS
 MEANS A QUANTITY IS INCREASING.
 MEANS A QUANTITY IS DECREASING.
I  R  I  R  IR
V=IR
SOLVE FOR I
MULTIPLIE BOTH SIDES BY 1/R
(1/R)V=IR(1/R)
V/R=IR/R
V/R=I R/R
V/R=I(1)
V/R=I
OR I=V/R
HOW CAN WE INCREASE I
I V / R
ONE WAY IS TO INCREASE V
 I  V  / RT
I V
 IS A SYMBOL FOR PROPORTION ALITY .
OR DECREASE R
 I V /  R
I IS INVERSELY PROPORTIONAL
TO R. AS R ↓, I↑
IF WE WANT TO DECREASE I, ↑R
 I V /  R
I IS INVERSELY PROPORTIONAL
TO 1/R. AS R↑, I↓
OHM’S LAW CIRCLE AND TRIANGLE
TRIANGLE FOR THE POWER EQUATION
POWER,CURRENT, RESISTANCE, VOLTAGE WHEEL
ANY VARIABLE ON THE POWER WHEEL
CAN BE FOUND USING THE FOLLOWING
TWO EQUATIONS.
1. V=IR
2. P=IV
EXAMPLE: P=V²/R
WHERE DID THIS COME FROM?
SOLVE EQ. 1. FOR I
V=IR
V/R=IR/R
I=V/R
SUBSITUTE
I=V/R INTO EQ. 2
P=IV
P=(V/R)V =V²/R
P=V²/R
DERIVE P=I²R FROM EQUATIONS 1. AND 2.
P=IV
SUB. FOR V=IR IN P=IV
P=I(IR)
P=I²R
ONE MORE TO TORTURE YOU!!!
SOLVE
V  PR
V  IR
SUB. FOR I=V/R
V  (P / V )R
V V  V ( P / V ) R
V 2  PR
V 2  PR
V  PR
ANDRIOD APP
APPLE APP
P-2
JOULE: UNIT OF ENERGY,TOO SMALL FOR PRACTICAL
USE. WATTS ARE USED INSTEAD, MORE ON THIS LATER.
There are two types of energy: potential or
stored energy, and kinetic or energy in
motion.
Potential energy is stored, or latent.
Energy can be stored in many ways
Kinetic energy is actual energy in
motion. Moving water, wind, and solar
radiation are examples of kinetic energy.
BARBELLS WITH P.E. UNTIL ITS DROPED
WRECKING BALL WITH HUGH AMOUNT OF K.E.
WORK IS FORCE MOVING THRU A DISTANCE
P-4
FOR 100%EFFICIENCY, Pout =Pin,
NOT POSSIBLE!!
VIOLATES THE LAWS OF THEMODYNAMICS
power out 10 j
EFFICIENCY 

 .1  10 percent
power in 100 j
MIL= ONE THOUSANDTH OF AN INCH
CIRCULAR MIL=TO THE AREA OF A CIRCLE WITH
A DIAMETER OF ONE MIL.
P-6
ATOMIC STRUCTURE OF ALUMINUM
ATOMIC STRUCTURE OF COPPER
Copper: The Miracle Metal
http://www.youtube.com/watch?v=sSVI5l-MbMQ&list=UU2bkHVIDjXS7sgrgjFtzOXQ
ATOMIC STRUCTURE OF SILVER
ATOMIC STRUCTURE OF GOLD
P-8
ELECTRIC FIELD LINES AROUND POINT CHARGES
UNLIKE CHARGES ATTRACT
LIKE CHARGES REPEL
CREATION OF SODIUM CHOLRIDE ION (SALT)
STATIC ELECTRICITY
ELECTROSTATIC PRECIPITATOR
DUST PARTICLES IN
NEGATIVE CHARGE PLACED
ON DUST BY GRID
Electrostatic Precipitator System Working.avi
http://www.youtube.com/watch?v=A0tDieiia_c
DUST REMOVED FROM AIR
BY ELECTROSTATIC ATTRACTION
WITH THE POSITIVELY CHARGED
PLATES