IGCSE Physics Notes. –. Contents. General Physics. . ..
Length & Time . ... Thermal Physics. . .. Simple Kinetic Molecular Model of ...
IGCSE Physics Notes
–
Contents
General Physics
.
Length & Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Speed, Veloci & Acceleration . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Mass & Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Densi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Densi of a Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Energy, Work & Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure
.
Pressure in Liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermal Physics
.
Simple Kinetic Molecular Model of Maer . . . . . . . . . . . . . . . . . . . .
Brownian Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermometers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Thermal Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Transfer of Thermal Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Properties of Waves
.
General Wave Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electricity & Magnetism
.
Simple Phenomena of Magnetism . . . . . . . . . . . . . . . . . . . . . . . . .
.
Elerical Quantities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Eleric Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Dangers of Elerici . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Eleromagnetic Effes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
Cathode Ray Oscilloscopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Atomic Physics
.
Radioaⅳi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.
The Nuclear Atom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appendices
A Symbols, Units & Definitions
B Equations Reference
List of Figures
Using a round boomed flask of known volume . . . . . . . . . . . . . . . . . .
Liquids ansmit pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Magdeburg Hemispheres. . . . . . . . . . . . . . . . . . . . . . . . . . . .
A mercury barometer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
List of Tables
General Physics
.
Length & Time
.
Speed, Velocity & Acceleration
.
Mass & Weight
.
Density ( Density
g kg or 3 3 cm m
) =
M ass (g or kg) V olume (cm3 or m3 )
ρ=
M V
ρ(H2 O) = 1 ± 0.1
.
g cm3
Density of a Gas to vacuum pump
scales Figure : Using a round boomed flask of known volume
. Take mass when emp (under vacuum). . Let air in and take mass. . The difference between the two masses is the mass of the air. . ρ =
M(air) V(f lask)
.
Forces
.
Energy, Work & Power
.
Pressure
Pressure ( P ressure
N or P a m2
) =
F orce (N ) Area (m2 )
P =
F A
1Pa = 1
N m2
1 bar = 105 P a
.
Pressure in Liquids
Pressure in a liquid is direly proportional to depth. d 100
P =
P ∝d P = kd
k=
P =
1 100
ρV g F = = ρgh A A
( ) ) ( ) ( N kg N P pressure, 2 = ρ density, 3 g gravity, h (height, m) m m kg kg m · kg · N N N ×m= = 2 × m3 kg m3 · kg m • Liquids ansmit pressure • Solids ansmit force
• At X: F = 1000 N A = 1 m2 1000 P = = 1000 P a 1
X
Y 10,000N 10m
1000N 1m2
Figure : Liquids ansmit pressure.
• At Y: F = 10, 000 N A = 10 m2 • Overall effe is equilibrium: 1000 P a × 10 m2 = 10, 000 N
30 cm
Force on hemispheres om atmosphere: surf ace area = πd2 ≈ 0.3 m2 ∴ F = P × A = 1 × 105
N × 0.3 m2 = 3 × 104 N m2
Figure : The Magdeburg Hemispheres.
.
Thermal Physics Simple Kinetic Molecular Model of Matter
• Eⅵdence for kinetic theory: – Brownian motion – crystals • Pressure laws:
vacuum me column
height of column depends on amount of a
a pushes down
p height of me pushes down equally me
Figure : A mercury barometer.
– liquids: p = ρgh – gases: p = ρgh Brownian Motion Brownian Motion occurs when inⅵsible molecules of a liquid or gas bombard a ⅵsible particle due to random thermal movement. If the ⅵsible particle is small enough (but still large enough to be clearly observed) it is seen to undergo Brownian Motion, i. e. a random mmoⅵng around, on an unprediable path, no net change of position. visible pa
molecules impacting pa
observed
visible
This theory supports kinetic theory because it is the only complete explanation, and it involves molecules (and/or atoms). Thermometers
Calibration
• we need fⅸed points:
– ◦C – ◦C • Place thermometer in: – melting ice – steam above boiling water Linearity allows us to fill in the scale Sensitivity the change in mercury level per change in temperature Range difference between the largest and smallest possile readings Thermocouples • Temperature difference across two ends of a wire produces a small voltage (potential difference) • Conneing a sensitⅳe voltmeter with a different pe of wire allows us to measure this voltage • The effe is not linear so a calibration table is required
. Thermal Properties . Transfer of Thermal Energy
Properties of Waves
.
General Wave Properties
. Light . Sound
.
Electricity & Magnetism Simple Phenomena of Magnetism
. Electrical Quantities . Electric Circuits . Dangers of Electricity . Electromagnetic Effects .
Cathode Ray Oscilloscopes
Atomic Physics
.
Radioactivity
.
The Nuclear Atom
Appendices A
Symbols, Units & Definitions
Quantity length area volume weight mass
Symbol(s) l, h, x . . . A V W m, M
Unit(s) km, m, cm, mm , , N kg, g
Quantity time density speed acceleration acceleration of free fall force moment of force (torque) work done power pressure atmospheric pressure temperature specific heat capacity specific latent heat frequency wavelength focal length refractive index angle of incidence angle of reflection/refraction critical angle voltage/P. D. current charge e. m. f. resistance
Symbol(s) t ρ u, v a g F M, τ, F W, E P p p θ, t c L f λ f n i r c V I Q E R
Unit(s) ,,s , ,,
N J W Pa, mbar ◦C , , Hz m, cm m, cm (dimensionless) ◦ ◦ ◦
V, mV , C, V Ω
B Equations Reference Weight
Speed
W =m·g
d s= t
Density ρ=
Acceleration
m V
Hooke’s Law ∆v a= t
F =k·x
Newton’s Second Law
Refractive Index
F =m×a
n=
cvaccum cmaterial
Moment of a Force Snell’s Law
M =F ×d
n=
sin i sin r
Kinetic Energy Critical Angle for TIR
1 E = mv 2 2
sin C = Gravitation Potential Energy E =m·g·h
1 n
Electric Circuits V =I ·R
Work Done ∆W = F · d Power P = Pressure p=
Electric Power P =V ·I
E t
Electric Energy Transfer E =V ·I ·t
F A
Total Resistance in Series Circuits
Liquid Pressure
Rtotal = R1 + R2 + R3 + · · ·
p=h·ρ·g
Total Resistance in Parallel Circuits
Boyle’s Law
1
p1 V1 = p2 V2
Rtotal
=
1 1 + ··· R1 R2
or
Energy to Raise Temperature
Rtotal =
E = m · c · ∆T Energy to Change State
R1 R2 R1 + R2
Voltage & Coils in Transformers
E = m · lf
Np Vp = Vs Ns
or E = m · lv
Voltage & Current in Transformers Wave Equation
Vs · Is = Vp · Ip
v =f ·λ
