Active Vrms 240 V

1
outside home
Active Vrms 240 V
Neutral
inside home
meters
Fuse 10 A Lights
Fuse 15 A Power
Fuse 20 A Hot water
Fuse 30 A Stove
2
N
Earth
No earth
N
A
A
Fuse blows protecting person
3
(No Transcript)
4
Neutral (blue)
A
DPST double pole single throw switch
N
E
Active (brown) Vrms 240 V
Earth (green / yellow)
5
R
T
P
U
Q
S
6
A
Relay trip coil
Applicance
N
Circuit breaker contacts
7
(No Transcript)
8
Antinode at level 5
Node at level 4
Antinode at level 2
9
translation
rotation
vibration
10
Motion Map for falling stone

v
v
a
v
F
v
11
A 81 m2
30 C
10 mm
k
Q
16 C
12
?
R2
R3
R1
13
220 W
1 kW
1.5 kW
4.7 kW
8 V
14
400 W
500 W
700 W
12.0 V
15
Free fall
Sliding to a stop


16
Fundamental
3 rd harmonic
17
Electric current i I (amperes A mA mA)


Like charges attract / opposite charges
repel Charged ions Na Cl- Ca2
-
-
High potential
Low potential
CURRENT I flow of charge

-
R
I3
Potential differnce V
I2
Kirchhoffs current law I I1 I2 I3
DQ
Wire free electrons Electrolyte or plasma
pos neg charges
I1
I
Dt
Heating effect
PHYSICAL QUANTITIRES
I
Current I i ampere (A) Charge Q q coulomb
(C) Charge density n C.(m-3) Cross section
area A (m2) Voltage V volt (V) Resistance R
ohms(W) Energy W joule (J) Time interval Dt
second (s) Power P watt (W)
devil
Resistance opposite to movement of charges
Magnetic field surrounds a wire currying a
current A wire carrying a current in a magnetic
field may experience a force
18
DIFFERENTIATION
INTEGRATION
Y
Y
Integral area under curve
Tangent to curve Slope gradient of tangent
a
b
X
X
19
Velocity v (m.s-1)
2D vx v cosq vy v sinq
1D

vy
Velocity is a vector
q
Physical quantities Velocity v u vo vi vf
(m.s-1) Displacement x y r s h d
(m) Acceleration a g (m.s-2) Time t Dt
(s) Mass m M (kg) Kinetic energy K
(J) Potential energy U (J) Momentum p
(kg.m.s-1 N.s)
slow fast
vx
x
v 0
Carl Lewis 100 m in 10 s vavg 10 m.s-1
a
v lt 0
v gt 0
Speed of sound 340 m.s-1 Speed of light c
3.00x108 m.s-1
1 m.s-1 3.6 km.h-1
Dv
t
Instantaneous velocity v dx/dt slope of
tangent to x/t graph
t
Special case a const
Change in velocity area under a/t graph
Conservation of energy U mgh K ½mv2 U K
constant
Force ? acceleration change in
velocity Newtons First law ?F 0 ? a 0 ? v
constant (straight line constant speed
standing in a bus) Newtons Second Law a ?F / m
hitting a golf ball, catching a cricket
ball, car going around a corner

v
Moving object Momemtum p mv Kinetic energy K
½mv2
Initial velocity t 0 v vo
vo
v vo a t
t
Collisions J Favg Dt mv2 mv1 W Favg Dx
½mv22 - ½mv12 Dt or Dx large ?? Favg small
Dt or Dx small ? Favg large
Impulse change in momentum Work done by a
single force on a particle change in KE
20
Horizontal
Vertical
sy
sx
t
0
0
t
vx
vy
t
t
ax
ay
t
t
0
0
21
(No Transcript)
22
8.0 V
1.0 k?
4.7 K k?
23
0 to 10.0 V
A
4.7 K
V
24
hot
cold
Dry ice (CO2) freezes 194 K (-79 C)
Iron melts 1803 K (1530 C)
Surface of the sun 6000 K
Water freezes 273 K (0 C)
Water boils 373 K (100 C)
Nitrogen boils 77 K (-196 C)
Absolute zero O K (-273 C)
25
TC (cold)
TH (hot)
Q (J)
Conduction
Thermal conductivity k (W.m-1.K-1) Copper k
385 Aluminum k 205 Brick k 0.5
Convection
Radiation
Water Specific heat capacity c 4190
J.kg-1.C-1 Latent heat of fusion (0 ) Lf
3.36105 J.kg-1 Latent heat of vaporization
(100 C) Lv 2.26106 J.kg-1
Change in temperature
Change in state (phase) Solid liquid -- gas
26
Y
X
a
a
Small m
m
Large m
(0,0)
(0,0)
F
m
m constant
F constant
Small m
27
Pythagorean theorem
For a right angle triangle with sides a, b and c
(hypotenuse) and with angles A, B and C 90?
B
c
a
Area of triangle ½ a b
A
C
b
28
v1 20 km.h-1
?t 20 min 20/60 h 1/3 h
v2 80 km.h-1
X
?x ? m
29
1
2
X