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A2 Physics Summary

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CIRCULAR MEASURE
Linear Displacement Displacement in a straight line
Linear velocity Rate of change of angular displacement
Angular Displacement Anglesubtended at the centre when an
position A to position B on a circular track
Angular velocity
Rate of change of angular displacement W O t
For A complete revolution
v
rW s
object movesfrom
linear velocity
It T
W
radius
We
298
angular velocity
x
CentripetalForce Force requiredfor an
XY Z havethesame object to move in a circle Is directedtowards
hey
t
If In
one centre or the circle
2
Fe
Fc MrW
Vx Ny Ve as Fe
my
verw considering
Mv w
theradiusratio Centripetal acceleration F ma
mas mu w
ma mu r mas mrw
Conical Pendulum
as rw
r
a
a NW
Radian Anglesuspended at the centre of a
F Fc sine circle by an arc equal to its radius
vertical Circular motion
T W COSA
Tmax MY't 008180
p
Feng
kg
Tano
Mmg
vg
Tan
Tan
HorizontalCircular Motion
I
Iw
Fc
T
1
Mv2
r
Imax
tm900270
Tma
0270
I
gooo
p
go
Imax Mf
Imax
p
Imax Yu
mg
mg
90
0900TmaxMftmgeos
w
Tmax
vitoFe T woos
mglosco
my mg
Niv
r
Tmax ME1mgCos
GRAVITATION
law ofGravitation Force of attractionbtw two pointmasses
is directly proportional to the product of the masses and inversely Fa GMima
proportional to the square of the distance btw their centres
R2
moon
Earth
Relationship b w g anda null Point
Earth
W a
moon
Newton's
magcon
Mlg Amfm
g GM
R2
pint
objectof
gig
mass m
id
Atthe null point t
MELHEM
Gravitational FieldStrength
g
Fr
distance'm
in
ofspace where amassexperiences aforce
GravitationalField Region
ofattraction experiencedby a unitman placedwithinthefield
Force
Satelliteorbitting a planet Geostationary Orbit equatorial orbit aboveequator
satellite
satellitemoves fromwesttoeast samedirectionas Earth
period is 24 hours same period as spinningon Earth
FcFa
m
ay
ma
M G
GMT
0 at infinity is zero
Wi 913
mus
KE 0.5
KE 0.5m Ft
0
Gravitational potential
GM
awayfrominfinity it becomes ve
field to move unit mass
work is done by the
towards the sourcemass o
DO Of 08
24 93
DO GE far
a
n
so am r
Gravitational PotentialEnergy work done in moving a point mass from
infinity to a point within the gravitational field eaknw 0
gg moon
Escape velocity
KE
MI
T2
Im
GaininGPElossinKE
3ham
ME
at surface
g Gig
g lg matmvesi
Vest
Gm Re o
129ft
2
Vesc
Vest
µ
GREGME
GERE
X
Ferpositionosboth
oedaugto
Omdgento
E DO m
E
ft
H
Eam
n
gift
If
grill ppl.mg
Engh
mi
Binary Star System
M
Ri yo
MZ
Ra
g
Fa
Fa
Fa Fc
Jim
anime MIRw2
Rita
Ri RI
SIMPLE
TE GMEM ar
y
Miike
rehang
TE KE APE
GMem
TEGMENz
GPE GME.me
y
ie dem
E
GPEDO.me
EK GMem
satellite
a
Derevation of GPEmgh Satelliteorbitting a planet
MIRIN
2
MzRzw2
MERWE MI
Rz
Mz RI
Harmonic MOTION
acceleration
Relation an x
x
SAMis oscillatory motion
Accelerationanddisplacement
proportional
Accelerationanddisplacement
inopposite directions
N
two
W
xo2
x2
Ellipse
Em
Choo
energy
Cho
xowasinw s.pro
D to
now
now
now
now
7 a wax
linked a walxosinwt
Velocity at SHM w IW nor x2
no maximum displacement a displacementfrommean position
PotentialEnergy
kinetic Energy
TotalEnergy
KE
12MV2
K E 12M W yo
W Xo x2
KEIM
now
potential
C
xosinwtddf xoweoswtdvdte
2
TE MaxKE
x O atMaxKE
TE Imway
y
KE PE
TE KE PE
pE
ymw2y2
GraphsforKEPEandTEagainsttime
mE1J
2
Energy
knw'tTotal
KE 42MW 103
ME 42mn40 ll Sinwt
KE12Mw2lxo3xo3in2wtpq.q.yzmwryo2
kinetic
42MW'd
ogzwtP.E 12mW'xisintut
PE
energy
Ho
Potential
Energy
FreeOscillations
intheabsence of a resistivemedium
DampedOscillations Oscillations occurring inthepresence of a resistivemedium
Oscillations occurring
LightDamping
air
moderateDamping water
Heavy Damping Honey
resonance Every mechanicalsystem hasits natural Kemeny of
oosillation fundamentalfrequency If frequencyof aforcedoscillator
Pa
Boyle's Law
v
If
y.fi
yY1fgg
fundamentalfrequency which results in a maximumtransferof
energyandtheamplitudeofthe mechanicalsystemreachesmaxvalue
2MAI
n
SICS
Vat
Charles law
Pat
Gay Lussac's law
IdealGas Formula PV n RT
n Moles of gas R UniversalGas Constant 8.31
pay
Pay
P Pressure V volumeofGas T Temperature Kelvin
Ideal Gas Assumptions a molecules move in constantandrandom motion
2 collisions betweenmolecules and container walls are completely elastic
3 Pressure is due to collisions between molecules andcontainerwalls
4 IdealGas molecules are free of anyintermolecularforcesof attraction
5 volumeof molecules is negligible in comparasionto the containervolume
Pressureof IdealGas D 43 Pecs
Derevation
Rn ex m
D
UniversalGasConstant
n
z
t
mass
e
C velocity
For molecule m
Bp
p
m Bex
m Rex
DP 2am
9m
E sp
s
Time
t 2L
Cx
E 2AM
IL CX
F
Cy
M
D Cx'm L
A
mi nm
piece m
v
ECZ
ECR
Cy's t ECE
ECz2
Lex'ssecy
3 0 23
ee
ed 3
D
I
ex2
Pee
Total KineticEnergy Average kineticEnergy Pv Nkt
M ee
32NRT 12MECD
32NRT 12Mees
IMU 12
32NRT N KMC 32ART N Yzma
3 2 PV N Zz KT
P 13 Pee
32MNRT 42MCC
312RNAT 42m62
D 43 Mv cc
PV NKT
Mee
32PV 42M C2
KE 32PV
3PV
312NRT
NA
Avogadro's constant
32 KT
Yam e CZ
AVG KE
32kt
Cprogimenanppeed
andTemperature
43040 MnRT
cr.m.sn T
go 311
k Boltzmann Constant
d MCAT Energy required toraise the temperatureof 1kg
of a substance by 10C I k
SpecificlatentHeat Q ML Energy requiredfor a 1kg substance to undergo a
change in state
Elimination oferror
internal Energy of Gases
Elimination oferror
latent Heatoffusion latentHeatofVaporisation TotalEnergy
KE t PE
t
t O k ml
IdealGases Total Energy KE
offo
0880
Pat ke mil Workdonebygas Px IN
Specific HeatCapacity
f
1114 11h41
SetupA
SetupB
Mi Ma l
L
O
mi me
ÉYÉiÉ
p
Pat Malek
Pit Mil Pat MIL
L
thPEP
WB
DWCon
compression
First law of Thermodynamics
DO DU t DW By
Du InternalEnergy
Da Energysupplied to gas
LECTROSTATICS
Columb's law Forceof attraction between two point charges is directlyF
gotQpg
proportional to theproductof the charges andinversely proportional
permitivityof
freespace
the square of the distancebetween their centres
Electric Field Strength Force per unit positive charge E
x
to
j q
Graphs of Electric Field Strength Electric Potential Workdone to move
a unit positivechargefrominfinity to a
against distance
Ent
point within the electric field
X
M
É
GraphOf Evs R
for a conductor E
Establishing
link
l
Ne Op
O
y qp
E
dr
day
q
q
IL
Graphs of ElectricPotential
againstdistance
WE
90N in EPE Loss in KE DNg
Fieldstrength MT'd
QS
a
of
w
avg
arvo's U
12mV's
ta um a
ng
rim
q
rim
I
ta
g
closest approach
e
r
field
done by the
Foran accelerating electron
Gradient of
we
chargemeans work
r
GraphofVvs R
L
sign is considered
rim
Distance
A
Q
ppgp graph
E Electric Electric PotentialEnergy
4780
du
a
x
B
OB
Coggin
KE gainin EPE
2112mn
q
yo Q
x
m
4
09
0
ULEMA
CAPACITANCE
Capacitance Ratio of the amountof charge stored on
potentialenergy
a
Electric
DELETE
II
Potential
Potential
raw
new
f
Q Cv
seriescapacitor
I
ElectricPotentialEnergy
V3
e 02oz 03C
t
Allcapacitors havesamecharge
capacitance a vintage
the plate with
go
Otc
c
I
t
t
z
d
I
MaxSafeWorking Voltage
Parallelcapacitors
Allcapacitorshavesamevoltage capacitor is ratedyou5,301
capacitance a
voltage
ElectricPotentialEnergy a capacitance
15 11 12 13
It
Discharging of a
03
2
you
v go
S
4301 OC too Or
C MTLEOR
capacitor
o
y
GUTCIVtC2V2tC3V3
CT Clt 2 03
Miko
Constant
T.me
IRC
R Resistance
ccapacitance
Timetakenfor a
I loethe v Voetre 0 0 ethe
capacitor
to discharge
MAGNETISM
of space where
a moving charge experiences a force
Fm Bgr B Magnetic Flux Density q charge v velocity
TY
CrossFieldmagneticandElectricFields are perpendicular
Fleming'sCAR
MagneticField Region
Fe
Fm
M at
Bar
Ism BqV Eq
mu
r
if
if
if
FB Fm FE
v eEB Fm e Fe
V FB Fm Fe
N
Bar
Fm Fe
HALLPROBE
Bgr Eq
BU E
v
d
v
N
Blige Y
I
nae
Blade
Vit B V Intel
d
Vit HallVoltage
v
start
End
Fm BIL Tesla B F1 Tesla is the unit of magneticfluxdensity I Tesla
of magneticfluxdensity occurs when a straight wire carrying a current 081A
perpendicular to the magnetic field exerts a force of IN per metre unitlength
Force of attraction between 2 wives
Torque Fm W
Fm B L
BIL W
Fm 2 107
BIA
2 L
B
2 10 7 I
d
Magneticfluxdensity
at a point perpendicular
fromthewire
I
q
7
Fm 2 10 Ii IzL
d
LECTRO MAGNETIC
for
BA
I IDUCTION
of turns
NBA
Faraday'sLaw Rate of change of magneticflux is the induced EMF voltage
J E Of 018 t or E doldt
in the circuit E DO t
Lena's law Lena's law can be used to determinethe
an
n number
directionofinducedcurrent in a solenoid Inducedcurrent
always flows in the direction apposingthechangecausing
it
Asthe magnet enters exits
thecoil mechanical energy is usedup
Damping
Overcoming Damping
Use a resistor as it
leads to lessercurrent
in overcoming attractive repulsiveforces
sima
tis
thereforelesser opposition
For a wire cutting a magnetic field E BLU
Eddy currents
Asthediscspins rateofcutting
magneticfluxlines is notthesame
foreverypartofthediscThismeans
differencesin
EMF inducedThis causeseddycurrentsTheseeddy
currents dissipateenergy therefore they cause a
amplitude energy
Lena's t Faraday'sLaw
Ea
B
a
o
En
n
do
It
I
N
g
LTERNATING CURRENTS
diode
Normal AC
Currentwave
v
HS
loss in
negative
gradientof
O us t
Half wave Rectification Full wave Rectification Advantage HalfWave
11
Lessercomplexity
n
Fullwave
lesser power loss
Na
on
I
Disadvantage Halfwave
Greater powerloss
vout
FullWave
e
A process bywhichthe outputvoltage More complex
does not fall to zero
Parallel capacitor combination
Smoothing
on
capacitor
current voltage in Al
1 losinwt N Vosinwt
Iims
Vms
Ig
Prins
Po
2
y
t
it
t
meansgreatersmoothing
Series capacitor combination
means lesser smoothing
Forsquare waves
Transformers
a No
puppy
Veg
StephSquare
steps mean
Step3 Root
3
To
Is
v02
Vo
hereUrms No
Tp
M Is
PPrimaryboil
f Secondary
witmberog
turns
VAN UM PHYSICS
ElectronVolt Theamount of kineticenergy an electron gains as it accelerates
19
througha potentialdifference of 1 volt eV Workdonein joules 1.610
Photon A photon is a quantum of electromagnetic radiation having a
h Planck's constant
fixed amount of energy Ehf
Workfunctionenergy Energyrequired
E 0 KE
work function to bring electrons to thesurface
ofthemetal
energy
Thresholdfrequency Minimum
frequency
hf info KE
fo thresholdfrequency for photoelectric effect
Dual Nature Of EMR
EMR can
proving it exists as waves
need a threshold frequency to happen proves
undergo diffraction
Photoelectriceffect
it exists as particles as in case of waves photoelectric effect would
haveoccurred at any frequency
Intensity Power
Enga
area
14nptphotoelectriccurrent
l np hf 89Iconstant npM
y
photoelectric current u
Electrons have a dual nature like EMR
De Broglies Equation wavelength of moving particles
n
momentum v
hp p
Photon Pressure
n 600 nm
P 2mW
v0
I
n Mmr
V2
240mhm
y
I axiom
h Mp
gyp
1 Photon3.31510195
2 Nophotons in Asecond6.0 1015
Power Np Energy
1 Energyof
time
3 Momentumof 1 photon 1.1111027ns
Nse DeBroglie's equation
Spectral lines
n
Absorpion
Ey
Ez
q
mtg
V9
42mV
Nq KELE
A
M
DE
Bar
D Bgr
mu
h
a
e em
MY BqV
f
Bgr
at
TY
M Total Momentum 6.63 1012ns
TotalMomentum np momentumof photon
5 Force
F DD
6.63 10 N
t
6 Pressure
P Force
5.53 10 6 Pa
Area
d How do spectral lines provideproof of discrete
energy
levels
spectral lines correspond to discrete wavelengths
Discrete wavelengths mean photons have a fixed amount
of energy
Emission
h
photons areemitteddue
to energy change of electrons
Fixed energychange means discreteenergy levels
Identifying gases through spectral lines
Gases have electrons in energy levels
certain wavelengths correspond to certain
photons whichelectrons
gain energy to
gofrom a lower to higher energylevel
Electrons thendeexcite and emit photons
in all directions
displayedon the
spectrum by darklines
These wavelengths are
NUCLEAR PHYSICS
Binding Energy Energy required
Infinity
E Dme
to split all
nucleons in a nucleus to
Fe 56
Binding
Energy
m mass defect
Bindingenergy pernucleon BindingEnergy ev
Total nucleons
Them
Fission Heavy nuclei split into lighter nuclei
Fusion lighternuclei fuse to form heavy nuclei
Fusion
Fission
MEnber
Energy Released Absorbed EBindingEnergy Products
EBindingEnergy Reactants
RADIOACTIVITY
t
t's half life Timetaken for the
at
m moe
activity of a radioactive sample to
Decayconstant n
nt's
half its initial value
Probabilityofdecay of a m Noe
nt
nucleusper unit time
c coe
Ao Aoe ath
Activity Bg
AN
A Aoe
A Activity of the sample
of sample
N Number of radioactive particles
C Count rate
m Mass
YE e nt
In la ntyz
Ln2 nth
2
th Ln
MEDICAL PHYSICS
X Rays
o
Production
at
look
Efent
to beemitted
y
from the cathode accelerating to theanode
is age
metal
filamentc athode
Anodecollision results in X Ray photon emission
Ill
Aluminium sheet blocks soft X
Rays no use for medicalpurposes
Attentuation Loss in intensity of x
due to exposure of living matter
rays
Ln u
I Joe u
u linear attentuation constant
Xyz
42 thickness that causes intensity to halve
Contrast X Rays Varying levels of blackness of differentobjectsin an image
How to increase
useartificial contrast increase exposure time
Thermionic emission causes electrons
Use slouroscent backing material
Sharpness
X Rays How well edges of different objects in an image
can be distinguished
How to increase Decrease size of anode plate
Reduce aperture size
CTScans ComputedTomography
Uses x
Rays
Object split into
Advantages
slices
Imageof eachslice taken
from multipleangles
Thousands
ofimagesofeach
slice processed to create a
2 Dimage
Done for all other slices
All slices 2Dimages
processed to make3D image
3 D image can be
rotatedand observed
can be done relatively quickly in
comparasion to
Provides
MRI
good contrast
can aid in treatment of brain
tumors
Disadvantages
Quite expensive
Exposure to large radiation dose
PET Scan
Positron Emission tomography
uses a radioactive tracer thats injected in the patient
What is atracer Substanceinjectedinto apatient absorbed by tissues
Howdoes thishelp Prevention of surgery therefore no risk of infection
Tracer Flourine 18 emits a positron
Positron is antimatter it searches for an electron and bothannihilate one
another
Annihilation releases
2 gamma photons ofequalenergy in opposite directions
Donutshapedgamma ray detector is placed around the patient
Time delay betweenthe 2 gamma
ray photons travelling to the
detector aids in finding exact location of annihilation
Ultrasound
Specific Acoustic impedance12 pc
Density of medium
How is it produced
speedof ultrasound in themedium
Ultrasound detectors contain Intensity Reflection Coefficient
yr
piezoelectriccrystals
Li 22
Lithe
u
Piezoelectriccrystals contain
Attentuation of ultrasound
positiveand negativesilver
A scan ultrasound
coated electrodes
ultrasound transmitters emitultrasound on the skinofthe
I toe
Currentappliedcausescrystals patient
Asthe ultrasound travels boundaries reflect a fraction
AC current causes crystals of the ultrasound whilethe rest penetrates
Thereflected wave is detected by thetransmitter
to vibrate
where the detected current is amplifiedandpulses
They vibrate at resonating
to change shape
frequencyproducing ultrasounds
Advantage
No seriousthreat as they
are displayed on a CRO
theecho time can be used to
of the boundary
do not containionizing
B Scan Ultrasound
radiations
A Bscan is a
Disadvantage
combination of
calculate the thickness
A scanwhich istakenfrom a
varietyofdifferentanglesTheindividualpulses obtainedaregathered
Forairfilled cavities e lungsanalysedandprocessed by a computer whichsuperimposes these
g
ultrasound is notused because multiple echoes on top of eachother thereby gathering a
imagelacks sufficientdetails twodimensionalimage
ND
STRONOMY
COSMOLOGY
L It is theabsolutemeasureof thetotalpower of theelectromagnetic
radiation emittedby a star
RadiantFluxIntensity F Luminosity passing normally through a surface perunit area
Year Distancetravelled bylight in a
F L
light
Fa
vaccum in a time of one
stud
year
StandardCandles It is a class of stellarobject whichhas a known luminosityand
whose distance can be determinedby calculation using itsradiantfluxintensity
Luminosity
I II
andluminosity
I
Wien'sdisplacement law The linkbtw observedwavelengthoflight
and temperature
amax a
T
amax b T
hated
beWiens Displacement Constant 2.898x 10 3mktYak
Stefan Boltzmann
law The luminosity of a star does not
thesurfacetemperature of the star It
4 MT8 T re
also depends on the physical state of the star
Stefan boltzmann law for luminosity 8 5.67 10 8 WM 2k 4
Doppler RedShift Theincrease in observed wavelength of electromagnetic waves
dependjust on
due tothe recession from thesource
Doppler BlueShift The decrease in observed wavelength of electromagnetic waves
due tothe advancement of thesource towards theobserver
off
DI
We
werelativevelocity ofstarfrom Earth
a speed of
light
no Wavelength in Lab
Hubble's law Therecessionalvelocity of a galaxy from Earth is proportionalto
thedistanceof the galaxy from Earth
Ho Hubble's constant workedout ur recessional speed of galaxy
Nra d
ur Mod d distanceof galaxy from Earth
Throughhubble's
It
law it
f
observed frequencyfrom star
correctly proves that
therefore provides evidenceof
Ageof theuniverse
1 Ho
the universe is constantly expanding
the BigBang
ZEESHAN ALAM KHAN
TEACHER SIR AFTAB SAAD
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