koofer
TRANSCRIPT
Find magnitude and direction
Charge expressed in sum of protons and electronsq = e ! Np " Ne( )
Coulomb s Law
F = kq1q2r2
k = 8.99 !109 N !m2
C 2
k = 14" #0
$0 = 8 85 !10%12 C 2
N !m2
Equilibrium Position (charge at origin and elsewhere is positive)
F1!3 = F2!3
kq1q3
x3 " x1( )2= k
q3q2x2 " x3( )2
x3 =q1x2 + q2 x1q1 + q2
Charged balls hang from ceiling with insulated ropes find massT sin! " Fe = 0 T cos! " Fg = 0
Fg = mg Fe = kq2
d 2
sin! =d / 2l
Fe = kq2
d 2= k q2
4l2 sin2!T sin!T cos!
=FeFg
m =kq2
4gl2 sin2! tan!
Force between electrons of electrostatic force and gravitational forceFeFg
=kq2eGm2
e
Bead on a wire slanted find mass of second bead
Fe = kq1q2d 2
Fg = m2gsin!
kq1q2d 2
= m2gsin!
m2 =k q1q2d 2gsin!
Fx = kq1q4d 2
+ kq2q42d( )2
cos45° = kq4d 2
q1 +q22cos45°!
"#$%&
Fy = kq2q42d( )2
sin 45° ' kq3q4d 2
=kq4d 2
q22sin 45° + q3
!"#
$%&
F = F2x + F
2y tan( =
FyFx
F =kq4d 2
q1 +q22cos45°!
"#$%&2
+q22sin 45° + q3
!"#
$%&2
( = tan'1
q22sin 45° + q3
!"#
$%&
q1 +q22cos45°!
"#$%&
Four charged objects find force on fourth charge
Chapter 21: Electrostatics
Electric Field from a point chargeEx =
F1,x + F2,x + ...+ Fn,xq0
Ey =F1,y + F2,y + ...+ Fn,y
q0Electric field do particles at center from 4 point charges
!Ecenter ,x = k
q2r2(! x) + k q3
r2(x) = k
r2q3 ! q2( )
!Ecenter ,y = k
q1r2(! y) + k q
r2(y) = k
r2q ! q1( )
Ecenter =!E2center ,x +
!E2center ,y
"kr2
q3 ! q2( )2 + q ! q1( )2 = 2ka2
q3 ! q2( )2 + q ! q1( )2
# = tan!1 q ! q1q3 ! q2
$%&
'()
Electric field everywhere on x axis (dipole)
E =q4!"0
1
x # 12d$
%&'()2 #
1
x + 12d$
%&'()2
*
+
,,,,
-
.
////
Vector electric dipole moment
!p = q
!d
Electric field far away from electric dipoleE =
p2!"0x
3
d = (10!10m)cos52 5° = 0 6 "10!10mp = 2ed = 2 "10!29Cm
Electric dipole moment of water
Electric field from three point charges
E1 = kq1b2!x
E3 = kq3a2!y
E2 =kq2 cos!a2 + b2
"#$
%&'!x +
kq2 sin!a2 + b2
"#$
%&'!y
E = E2x + E
2y
! = pE sin"Torque on electric dipole
Electric flux! = EAcos"
! =
!E "d!A"##
Guass s Law
! =
!E "d!A ="##
q$0
cyclindrical symmetryE =
!2"#0r
=2k!r
planar symmetryE =
!2"0
planar symmetry conductorE =
!"0
Charge distributed uniformly throughout sphere insideEins de =
!r13"0
Eins de =Qr1
4#"0R3 =
kQr1R3
Eoutside =kQr22
outside
Electric field from a ring of chargeEz (z) =
kdqr2! cos" = k dq
r2zr!
r = z2 + R2 dq = q!Ez (z) =
kqzz2 + R2( )3/2
ay =Fm
=qEm
y = 12at 2 L = vt
a = 2y(L / v)2
=2yv2
L2
m =qEa
Mass of inkdrop on inkjet
Chapter 23: Electric PotentialConstant electric field
Electric field
Electric field at x
!E(!x) =
!Fq0
= kqr2r
Charge in a cube one of the sides!oneface =
!6=16Q"0
Chapter 22: Electric Field
W = q!E !!d = qEd cos"
displacement same direction as e # fieldW = qEd $U = #qEddisplacement opposite direction as e # fieldW = #qEd $U = qEd
V =Uq
!V = "We
q
Electric Potential
K = !"U = ! q1V + q2 (!V )[ ]K =
12mv2 # v = 2K
m
Energy of tandem acc
!V = "We
q= 0#V is cons tan t
0 Work constant V
W = q
!E !d!s
i
f
"Work
!V = Vf "Vi = "
We
q= "
!E #d!s
i
f
$Potential Difference
PotentialV (r) = kq
r V (!x) =
!E !d!s
x
"
# V = Vii=1
n
! =kqirii=1
n
!
V =kqirii=1
3
! = k q1r1+q2r2
+q3r3
"#$
%&'= k q1
b+
q2a2 + b2
+q3a
"#$
%&'
Superposition of Electric Potential
ES = !"V"s
U = q2V1(r)
U =kq1q2r
U12 =W = q2V = q2kq1d
W13 +W23 =U13 +U23 = q3V = q3kq1d+ q3k
q2d
V (C) = q1R+q2R
+q3R
V (C) = k !eRi=1
12
" = k !12eR
E(C) = 0
Calculating Field from Potential
Electric Potential from two charge system
Electric Potential of triangle system
Electric Potential from charges at center
12 electrons circle
C =qV
=!0Ad
Farad
Capacitance of a parallel plate capacitor
Area of a parallel plate capacitor
Cylindrical capacitor Spherical capacitor
Single conducting sphere capacitor
Chapter 24: Capacitors
Circuit in parallelCircuit in series
Work required bring capac to full charge
Work stored as EP energy for capacitor
energy density
EP energy for parallel plate cap
Thundercloud find potential diff EF and total E
Energy stored in capacitors (xJ) Dielectric cons
C =! 2"#0Lln r2 / r1( )
Capacitance of a coaxial cable
Capacitor half filled with a dielectricCharge on a cylindrical capacitor
E =Eai
!=
q!"0 A
=q"A
" =!"0
C =!Cair
C =
!0 Ad
; V =q / 2C
; E =Vd
;U =12
qV
A =
dC!0
q = (C1 + C2 + ..Cn )VCeq = C1 + C2 + ..Cn
Ceq = Cii=1
n
!
V = V1 +V2 +V3 = q 1C1
+1C2
+1C3
!"#
$%&
V =qCeq
1Ceq
=1Cii=1
n
'
Wt = dW! =12q2
C
U =12q2
C=12CV 2 =
12qV
u = UAd
=CV 2
2Ad=12!0
Vd
"#$
%&'2
=12!0E
2
U =12CeqV
2 =12nCV 2
n = 2UCV 2
C =! 2"#0Lln r2 / r1( )
q = CV = ! 2"#0Lln r2 / r1( )
$
%&'
()V
u =U
volume 1F =
1C1V
C =qV
=!L
!2"#0
ln r2 / r1( )=
2"#0 Lln r2 / r1( )
C = 4!"0
r1r2
r2 # r1
False: A negative charge placed in Zone 2 can be in equilibrium True: A positive charge placed in Zone 3 can be in equilibrium True: A negative charge placed in Zone 3 can be in equilibrium True: A negative charge placed in Zone 1 can be in equilibrium True: A positive charge placed in Zone 1 can be in equilibrium False: A positive charge placed in Zone 2 can be in equilibrium 0: charge o the hydrogen atom, consisting o a proton and an electron -1/3: charge o the down quark 0: charge o the neutron +2/3: charge o the up quark 0: charge o the helium atom, consisting o two protons, two neutrons, and two electrons -1: charge o the electron +1: charge o the proton
F = k q1q2r2
! k e2
c2* 2 * b
c
radius = atmosphere + earth
# of protons = rate* time* (4!r2 )total charge = # of protons * (1 602i10"19 )
Cosmic rays bombarding Earth find total charge
kg *1000gkg
*1molxg
* 6.023*1023atoms
1mol* #.of .electrons
1atom
Electrons on mass of water
F = kq1q2d 2
4.3F = kq1q2xd 2
x =14.3
= 0.232
new.dis = 0.232 *d 2
How far apart two charged spheres
Ratio of electrostatic/gravitationFe = k
q1q2r2;Fg = G
m1m2
r2
Fe / Fg !k q1q2r2
G m1m2
r2
Two beads on insulating string find mass of sec beadFe = Fg
Fe = kq2
d 2;Fg = mg
m =k q
2
d 2g
Fe = kq1q2d 2
Fg = m2gsin!
kq1q2d 2
= m2gsin!
d =k q1q2m2gsin!
Two beads slanted wire find force between
T sin! " Fe = 0 T cos! " Fg = 0
sin! =d / 2l
Fg = mg Fe = kq2
d 2=
q2
2l sin!( )2=
q2
4l2 sin2!T sin!T cos!
= tan! =FeFg
l = kq2
4gmsin2! tan!
Two balls on wire find length of string
kq1q3
(x3 ! x1)2 = k
q3q2(x3 ! x2 )
2
q1 (x3 ! x2 ) = q2 (x3 ! x1)
x3 =q1x2 ! q2 x1q1 ! q2
One pos charge on origin and neg charge find position of third
CAPA #1
CAPA #2Square, pos charge and neg charge diagonal, find E at other corners
wo point charges at corners o right triangle, fine E o third and direction o E
Hollow metal sphere with a solid sphere insidetotal charge surface of inner sphere
total charge on inner surface of hollow sphere
total charge surfaceof outer surface
Max torque with dipole moment measured in D
Net orce o water molecule near point charge
wo semicircular shaped insulating rods find E at center
Ex =!2kq"r2
2Ex
E needed to counteract weight o e- at Earth s sur ace
Ratio o two di erent wires, charge density lamda and radius r
CAPA #3
Speed of e- w th VK = !"U = !qV
K =12mv2
v = 2Km
#2(qV )m
Two ons w th +1 and -1 charge, find work to nc. d stW = q!V
"W = q k qdi
# k qd f
$
%&'
()
Battery w th two para e meta p ates, acc from neg to pos p ate, fine KE and speedK =U = qV K =U = qV K =
12mv2
qV =12mv2 ! v 2qV
m
K = q!V = (16qe )!VP = (16qe )!V " (rate)
Acc erator str ps eʼs at a rate, find power
V = k qr! "V = k 4q
a2
#$%
&'(2
+ b2
#$%
&'(2
Four same point charges at corners of rectangle fine potential at center
Hollow spherical conductor with surface charge
Voutside =kQR
Vinside =kQR
=Q
4!"0RFour point charges on corners of square three pos and one neg find V at certain point above centerk qr! = k q + q + q " q
a2 + a2 + c2
# k 2q2a2 + c2
Ex = !"V"x
Ey = !"V"y
Ez = !"V"z
ie(x2 + xy2 + yz)
Ex = !"V"x
= 2x + y2
Ey = !"V"y
= 2xy + z
Ez = !"V"z
= z
Find V from equation of volume with certain coordinates
nsulating sheet with charge distribution uni orm ind change in V when charge is moved rom position A to B
!0!Eid!A""" = !0 EA + EA( ) = q = #A
E =#2!0
;W = QEd cos$
%W =Wf &Wi = Q#2!0
'()
*+,dy1 &Q
#2!
')
*, dy2
V = &%WQ
Surface area of capacitor
A =Cd!0
Capacitor Defibrillator charged find capacU =
12CV 2
C =2UV 2
Capacitor with mylar between plates find work to remove mylar and potential difference one Mylar is removed!W =Wi "Wf
#12CV 2 "
12C$V$( )2
V =!V
Parallel plate capacitor find charge energy stored area and if filled withdielectric
q = VCU =12qv A =
dC!0
C =! "0Ad
C =! 2"#0Lln r2 / r1( )
Two soup cans filled with soup
Chapter 25: Direct CurrentsElectric current
i = dqdt
q = dq! = i dt0
t
!
1A =1C1s
ontophoresis
q =amount
applicationrate
q = it ! t =qi
Current Density
Dri t Velocity
Current through a wire
Resistance
Resistivity
Resistance o Wire
Convert rom AWG size to wire diameter
emp dependence o the resistivity o metals
emp dependence o the resistance o conductor
Ohm s Law
Resistors in Series
nternal Resistance o Battery example
J =
iA
i = dqdt
= nevd A
J =iA= nevd
J = di / dA
Aoute ' = !R2 " ! R / 2( )2= ! 3R2
4i = JA '
R =Vi=
ELJA
=!LA
1" =1V1A
! =EJ
units = VmA
= "m R = ! L
A
d = 0 127 !92 36" AWG( )/39 mm
! " !0 = !0# T " T0( )
R ! R0 = R0" T ! T0( )
Vemf = iR
Vemf = iR1 + iR2... = iReq
Req = Rii=1
n
!
i =V / RVt = iReq = i R + Ri( )R + Ri( ) = Vt
i
Ri =Vt
i! R
nternal Resistance o Battery
Resistance in Parallel (have same voltage)current is sum o individualPower in Electric circuits
Energy
emp Dependence o the Resistance o a Light bulb
Galvanometer as current-measuring device
Dri t velocity o e in copper wire
i =V / RVt = iReq = i R + Ri( )R + Ri( ) = Vt
i
Ri =Vt
i! R
i =Vemf
1Req
1Req
=1Rii=1
n
!
P = iV = i2 R =
V 2
Rwithi = V
RandV = Ri
1kWh = 1000W i3600s = 3 6i106 joules
Power whenlighted
P =V 2 / R ! R =V 2 / P
R0 =R
1+" T # T0( )
V = i nt Ri;V = imax Req
!V = i nt Ri = imax Req
1Req
=1Rii=1
n
" =1Ri
+1Rs
!imax
iint Ri
=1
Req
=1Ri
+1Rs
Rs = Ri
iint
imax # iint
x = vdt;iA= nevd
n =# conductionelectrons
volume
n =1electron
atom6.02i1023 atoms
Xgdensity g
cm3
1.0i106 cm3
m3
vd =i
neA
x = vdt =i
neA!"#
$%&
t
Chapter 26: CircuitsKircho s Junction Rule
Kircho s Loop Rule
Charging a batteryWheatstone bridge
Voltmeter in a simple circuit
Capacitor ully charged
Capacitor discharging
ime to charge a capacitor
i1 = i2 + i3he sum o voltage drops around a complete circuit loop must
sum to zero
!iRi !V +Ve = 0Ve = iRi +V
loop adb :!i3R3 + ig Rg + i1R1 = 0
loopcbd :+iu Ru ! ig Rg ! iv Rv = 0
junctionsi1 = ig + iui3 + ig = ivWhenbridgebalancedi1R1 = i3R3;iu Ru = iv Rv
i1 = iu ;i3 = ivFinallyiu Ru
i1R1
=iv Rv
i3R3
" Ru =R1
R3
Rv
Before
i =VR
Connected
1Req
=1R+
1Rv
! Req =RRV
R + RV
i =VReq
qtot = CVemf
q = q0e!
tRC
"#$
%&'
i = dqdt
=q0
RC"
#$%
&'e
!t
RC"#$
%&'
q(t) = q0 1! e!
tRC
"
#$%
&'
t = !RC ln 1!q(t)q0
"
#$%
&'ime constant o circuit
Rate o energy storage in a capacitor
q = q0 1! e!
tRC
"#$
%&'
"
#$$
%
&''
whereq0 = CVemf ;( = RC ;V (t) = q(t) / C
V (t) =Vemf 1! e!
tRC
"#$
%&'
"
#$$
%
&''=Vemf !Vemf e
!t
RC"#$
%&'
RC = ( =!t
ln! V (t) !Vemf( )
Vemf
"
#$$
%
&''
q = CV 1! e! t / RC( )U =
12
q2
CdUdt
=qC
dqdt
=qC
i
"CV 1! e! t / RC( )
CVR
#$%
&'(
e! t / RC =V 2
Re! t / RC 1! e! t / RC( )
Chapter 27: MagnetismLorentz orce
Magnetic orce on moving chargeesla
Guass
Proton in B ield (find orce)
Cathode Ray ube (calc vel and acc)
Particle Orbits in Uni orm B
Mass spec , find mass
Momentum o a track (find momen and speed)
Period, req, and ang req o particle in orbitDeuteron in Cyclotron
Magnetic field (Hall e ect)
Hall probe (find mag o magnetic field)
orce on a current carrying wire
orque on a current carrying loop (square and circle)
Magnetic Dipole Momentum
Magnetic potential energy in external magnetic field
riangle Shaped Loop
!F = q!v !
!B( !x)
FB = qvBsin!
1T = 1
NsCm
= 1NAm
1G = 10!4T
K =12
mv2 ! v =2Km
F = qvBsin"
!K = "!U = qV
12
mv2 = eV # v =2eV
m
F = ma = qvB # a =qvBm
m vr= qB !
pr= qB
!K = 1 / 2mv2;!U = "qV
!K + !U = 0 #1 / 2mv2 " qV = 0
v =2qV
m
r =mvqB
# m =B2qx2
8V
p = mv = erB
vc=
mvmc
T =2!r
v=
2!mqB
f =1T=
qB2!m
" = 2! f =qBm
B =
2!mfq
B =
VH
dv=
VH dhnedi
=VH hne
i
n =# electrons
volume
n =1electron
atom6.02i1023 atoms
Xgdensity g
cm3
1.0i106 cm3
m3
B =VH hne
i
q = ti =Lv
i;(v is drift velocity)
F = qvBsin! =Lv
i"#$
%&'
vBsin!
( F = iLBsin!
!! = !r "
!F
! = iaB( ) a2
#$%
&'(
sin) + iaB( ) a2
#$%
&'(
sin)
* ia2 Bsin) = iABsin)
µ = NiA
U = !µBcos"
hypotenuseF = i
!L !!B
i!L ||"B " F = 0
x # sideBx = #Bcos$ = 0
By = Bsin$
$ = tan#1(Opp / Adj)F = iLx By
current is constant
Vemf =V1 +V2
voltage is constant
i = i1 + i2
Chapter 28: Mag Fields of Moving ChargesMagnetic ield
B ield rom a Long, Straight Wire
B ield rom a Loop
Parallel Current Carrying Wires
B orce on wire rom two other wires
orce on square LoopB ield inside long wire
B ield inside ideal solenoid
B ield inside toroid
ind vel where net orce on E and B is 0 (pos charge)
B ield rom Current Distribution
B field rom Current distribution (3 circuits)
B field o Long wires, find point where B field is 0
Circular motion, find speed and radius taken
Atoms as magnets
dB =µ0
4!idssin"
r 2
µ0 = 4! #10$7 TmA
B r!( ) = µ0i
2"r!
B =
µ0i2R
F12 = i2 L
µ0i2!d
"
#$%
&'=µ0i1i2 L2!d
Bb =µ0ib2!d
; Bc =µ0ic
2! 2d( )Bbc =
µ0ib2!d
"µ0ic4!d
=µ0i
4!d
Fabc = ia LBbc =µ0i
2 L4!d
Fdown =µ0i1i2 L
2! 0.100m( )Fup =
µ0i1i2 L2! 0.100m + 0.250m( )
F = Fup " Fdown
Ampere s Law
!B ! d!s"" = µ0ienc
B r!( ) = µ0i
2"R2
#
$%&
'(r!
B =
µ0 Ni2!r
q!E ! !v !
!B( ) = 0
qE = qvBsin 90°( )v =
EB
1 dB1 =µ0
4!idssin 0°( )
r 2 = 0 " B1 = 0
2 dB2 =µ0
4!idssin 180°( )
r 2 = 0 " B2 = 0
3 B3 = dB# =µ0
4!iRd$R2 =
0
! / 2
#µ0i2R
%
&'(
)*
f om fieldat cente ofloop
=µ0i ! / 2( )
4!R=µ0i8R
Upper ! half
" = # R = 3r Buppe =µ0i
12Ra and b
BR= "=# =µ0i4r
c
BR= "=# / 2 =µ0i8r
BR=2 "=# / 2 =µ0i16r
Final
Ba =µ0i
12R+µ0i4r
=µ0i3r
Bb =µ0i
12R!µ0i4r
= !µ0i6r
Bc =µ0i
12R+µ0i16r
+µ0i8r
µ0i12!r
=µ0i2
2! d " r( )i1r=
i2d " r( ) # r =
i1 d " r( )i2
12
mev2 = eV ! v =
2eVme
Fcent =mev
2
r; Fmag = vBe
vBe =mev
2
r! r =
meveB
Current
i =eT=
e2!r( ) / v
=ve
2!r
Magnetic moment
µo b = iA =ve
2!r!r 2 =
ver2
Orbital angular momentumof e"
Lo b = rp = rmv
# Lo b = rm2µo b
er$
%&'
()=
2mµo b
e
Magnetic Dipole Moment!µo b = "
e2m!Lo b
B = µ0 in;wherenis# turns per unit length
!B =!B0 + µ0
!M ;!H =
!B / µ0!
B = µ0
!H +
!M( ) = µ0 1+ !m( ) !H
Re lative permeability" m = 1+ !m
Magnetic permeabilityµ = 1+ !m( )µ0 =" mµ0
Magnetic Prop o matter
Chapter 29: Electromagnetic InductionMagnetic flux
araday s Law o nduction
nduction in a flat loop
Special cases or flat loop
Changing B ield, current inc according to current, find induced voltage at loop
!B =!Bid!A"" = BAcos#
1Wb = 1Tm2
Vemf = !
d"B
dt
Vemf = !Acos" dB
dt! Bcos" dA
dt+# ABsin"
A,! cons tan t Vemf = "Acos! dBdt
B,! cons tan t Vemf = "Bcos! dAdt
A, Bcons tan t Vemf =# ABsin!
A = N!R2
B(t) = B0 1+ 2.4s"2t2( )A,# cons tan t Vemf = "Acos# dB
dt
Vemf = "Acos# ddt
B0 1+ 2.4s"2t2( )( )= "Acos# B0 2.4s"2 2t( )
Motion Voltage, find induced voltage as a unction o time
Lenz s Law - our Cases
nduced Voltage on a Moving Wire in B ield
nduced em , field o a solenoid, find induced em due to changing field
nduced em
nductance
RL Circuit, switch connected
A(t) = w ! d(t) = w ! d " vt( );t f = d / v
Vemf = "Bcos# dAdt
= "Bcos# ddt
w ! d " vt( )( )Vemf = wvBcos# from0tot f
a) An increasing magnetic field pointing to the right induces a current that creates a magnetic field to the leftb) An increasing magnetic field pointing to the left induces a current that creates a magnetic field to the rightc) A decreasing magnetic field pointing to the right induces a current that creates a magnetic field to the rightd) A decreasing magnetic field pointing to the left induces a current that creates a magnetic field to the left
V = vLB
B ! field of outer solenoidB = µ0in = µ0iN / L;i =V / R
voltagetimedependV =V0 sin(t)
Induced emf
Vemf = !Acos" dBdt
find derivative
!E ! d!s = "
d#B
dt"$
N!B = Li
L"# $% =!B"# $%i"# $%
&1H =1Tm2
1A
µ0 = 4' (10)7 H / m
Vemf L = !L didt
Vemf ! iR ! L didt
= 0
i(t) =Vemf
R1! e! t / " L( )( );" L = L / R
nductance o a solenoid
Sel induction
RL Circuit, em suddenly removed
L =
N!B
i=
nl( ) µ0in( ) Ai
= µ0n2lA
Vemf L = !
d N"B( )dt
= !d Li( )
dt= !L di
dt
i(t) = i0e
! t /" L ;i0 =Vemf / R
RL Circuit solenoid, how long current to reach hal
L didt
+ iR =Vemf i(t) =Vemf
R1! e! t / L / R( )( )
12
Vemf
R=
Vemf
R1! e! t0 / L / R( )( )
12= 1! e! t0 / L / R( ) "! ln2 = !t0 / L / R( )
t0 =LR
ln2
nstantaneous power provided by em source
Energy stored in B field o the inductor
P =Vemf i = L di
dt!"#
$%&
i
U B = P dt
0
t
! = Li 'di '0
i
! =12
Li2
Chapter 30: Electromagnetic Oscillation and Currents
chargeas a functionof time
q = qmax cos !0t + "( )angular frequen
!0 =1
LCcurrent
i = #imax sin !0t + "( )imax =!0qmax
electrical energy
U E =qmax
2
2Ccos2 !0t + "( )
magneticenergy
U B =L2
i2max sin2 !0t + "( ) = qmax
2
2Csin2 !0t + "( )
energy incircuitU =U E +U B
=qmax
2
2Ccos2 !0t + "( ) + qmax
2
2Csin2 !0t + "( )
=qma
2
2Csin2 !0t + "( ) + cos2 !0t + "( )( ) = qmax
2
2C
LC Circuit
RLC Circuit
rateof energy lossdUdt
= !i2 R
chargeas a functionof time
q = qmaxe!
Rt2 L cos "t + #( )
angular freq
" = " 20 !
R2L
$%&
'()
2
where "0 =1
LCenergy incircuit
U E =q2
max2
2Ce!
RtL cos2 "t + #( )
oscillation freq
!0 =1
LCenergy stored
U =qmax
2
2C=
CVemf( )2
2Cchargeof capac at giventime
q = qmax cos !0t + "( );q = qmax when" = 0
q = qmax cos !0t( )
LC Example
sinusoidal voltageas functionof timevemf =Vmax sin!t
induced current
i = I sin !t "#( )voltageand current amp.acrossresistorVR = IR R
capacitivereac tan ce
XC =1
!Ccurrent incircuit
iC =VC
XC
cos!t = IC sin !t + 90°( )voltageand current amp,acrosscapac.VC = IC XC
inductivereac tan ceX L =!L
curent in inductor
vL = iL X L $ iL = "vL
X L
cos!t = IL sin !t " 90°( )voltageand current amp,across inductorVL = IL X L
current incircuit
I =Vmax
R2 + X L " XC( )2
impedance
Z = R2 + X L " XC( )2
phasecons tan t
! = tan"1 VL "VC
VR
#
$%&
'(= tan"1 X L " XC
R#
$%&
'(
For XL > XC, φ is positive, and the current in the circuit wi l lag behind the voltage in the circu tFor XL < XC, φ is negative and the current in the circuit will
lead the vo tage in the circuitFor XL = XC, φ is zero, and the current in the circuit will be
in phase with the voltage in the circuit
rateenergy is dissipated intheresistor (Power)
P = i2 R = I sin !t "#( )( )2R = I 2 Rsin2 !t "#( )
average power
P =12
I 2 R =I
2
$%&
'()
2
R; I ms =I
2
* P = I ms2 R = I msVmax ms
RZ= I msVmax ms cos#
max when# = 0socos# is power factormisc.
V ms =V
2
Vmax ms =Vmax
2current
I ms =Vmax ms
Z=
Vmax ms
R2 + !L " 1!C
$%&
'()
2
Energy and Power
Vemf =Vmax sin!t
Vemf = "Nd#B
dtrelationshipVP
N P
=VS
NS
powerPP = IPVP = PS = ISVS
secondary current
$ IS = IP
VP
VS
= IP
N P
NS
primary current
IP =NS
N P
IS =NS
N P
VS
R=
NS
N P
VP
NS
N P
%
&'(
)*1R
=NS
N P
%
&'(
)*
2VP
R
Pr imary resis tance
RP =VP
I=VP
N P
NS
%
&'(
)*
2R
VP
=N P
NS
%
&'(
)*
2
R
rans ormers
wo di erent wires, find ratios o current densities and dri t velocities
ind max resistance o rectangular wa er
ubular resistor, find resistivity and % change in resistance
ind Current at R3
J = iA;A = ! d
2"#$
%&'2
JCu =i
! dCu / 2( )2; JAl =
i! dAL / 2( )2
JCu / JAl
J = i / A = nevd
vd =Jne
vd ,Alvd ,Cu
=JAl / nAlJCu / nCu
Current Density Drift Velocities
R = ! LA
arrangeinwaythat dividesby smallest area possible
! =RAL;A = "route
2 # "rinne2
! = R"route
2 # "rinne( )L
R ! R0 = R0" T ! T0( )Rnew = R0" T ! T0( ) ! R0Percentage Increase = Rnew / R0 !100%
Resistivity Percentage Increase
Equivalent Resistance
V = iR
i = VR=
V2R3
R12 =1R1
+1R2
!"#
$%&
'1
Rop= 2R12 + R3 = Rbo tom
Req =1R
op
+1
Rbo tom
!
"#
$
%&
'1
Battery, internal resistance ind resistance to extract certain power rom R = resis tanceoutsidebatteryr = int ernal
P =V 2RR + r( )2
SolveR
3 resistorsind R to produce certain currents i1 and i2
Vemf = i120! + i2 R
orVemf = i2 R
What Vem will produce currents i1 and i2
ind currents with resistance values and Vem values
Vemf 1 ! i1R1 ! i3R3 = 0
Vemf 2 ! i2 R2 ! i3R3 = 0
i1 + i2 = i3Re arrange for matrixi1R1 + 0 ! i3R3 = !Vemf 1
0 ! i2 R2 ! i3R3 = !Vemf 2
i1 + i2 ! i3first matrix
R1 0 R3
0 R2 R3
1 1 !1
"
#
$$$$
%
&
''''
second matrix
!Vemf 1
!Vemf 2
0
"
#
$$$$
%
&
''''
R1 0 R3
0 R2 R3
1 1 !1
"
#
$$$$
%
&
''''
!1
i
!Vemf 1
!Vemf 2
0
"
#
$$$$
%
&
''''
ind currents with resistance values and Vem values
RX =
1m ! L( )L
iR1
Resistance needed to produce peak power output
P =V 2 / RR = P / V 2
q = q0e!
1RC
"#$
%&'
t = !RC ln(1! % change)
ime to charge capacitor to percentage
Current through 4 ohm resistor
Potential di erence across R1
Potential di erence across R2
Potential di erence across capacitor
Vemf ! iR1 ! iR2 ! i" = 0
i =Vemf
R1 + R2 + "i = 0
i =V
R1 + R2
Potential Difference = iR1
i =V
R1 + R2
Potential Difference = iR2
sameas R2
Charge on C1 when switch is closed
Charge on C2 when switch closed
Charge on C1 and C2 when switch is open
iR !qC
= 0;i = VR1 + R2
q =V
R1 + R2
"
#$%
&'RC
iR !qC
= 0;i = VR1 + R2
q =V
R1 + R2
"
#$%
&'RC
q =V
C1C2
C1 + C2
Wire placed at angle with magnets at ends. Find F
! = 90 " angle givenF = iLBsin!Proton entering two-plate region, find B field
Calculate radius of trajectory of proton in B field
Calculate the period of motion in plate, freq, and pitch
Value of current of wire2 that is half of wire1
Square ammeter clamped on DC current, find current
B field inside solenoid
B field inside tungsten wire with current a distance from its central axis
Aircraft, find potential diff. between wings
Loop expanding, find ind. current
Motor, single loop find max angular speed
How long will it take circuit to reach certain current
Wire moving in xy plane, find vel to induce certain pot. diff
Fully charged cap. connected to inductor, find max current and freqAC power on RLC Circuit
Transformer
V = Ed; E = vBV = dvBa
V = !Bcos" dAdt
; A = #r 2 = # r0 + vt( )2
V = !Bcos" ddt
# r0 + vt( )2( )V = !B# cos" 2r0v + 2v2t( )V = iR $ i =V / R
Vemf =! ABsin";sin90°
! =Vemf
ABsin"
i(t) = i01! e! t / L / R( );i0 =Vemf / R
t = ! lni(t)i0
"LR
F = qvBsin! with! = 90°
E = vB =Vd" v =
VdB
imax = w0qmax
where w0 =1
LCand qmax =VC
imax =1
LC
!"#
$%&
VC( )
f =
!0
2";!0 =
1LC
X L =!L
Z = R2 + X L ! XC( )2
I =Vmax
R2 + X L ! XC( )2
VR
R= IR sin!t
VR = IR R
VC = IC XC where IC is imax
VL = IL X L where IL is imax
VP
N P
=VS
NS
!VS =VP
NS
N P
IS = IP
VP
VS
= IP
N P
NS
Resistor and Capacitor, what freq and current where potential drop across cap. equal across resistor
XC = R =1
!C"! =
1RC
f =!2#
=1 RC
2#
I =Vmax
R2 + X L ! XC( )2
=Vmax
R2 + XC( )2=
Vmax
2R22
XC =
1!C
=1
2" fC
!0 =1LC
= 2" f
!02 =
1LC
C =1
L!02 =
1
L 2" f( )2
VR = IR R;VC = IC XC ; IR = IC
VR
R=
VC
XC
R =VR
XC
VC
=VR
1 / !C( )VC
= VR
1 / 2" fC( )VC
Design own RLC find C and R
Maxwell ampereʼs law
Displacement current
Displacement current with wire going through
Wave equations
Wave solution
Speed of light
Rate of energy by an electromagnetic wave
Instantaneous power per unit area
Intensity
Energy density in electromagnetic wave
Intensity and force of radiation
Pressure due to electromagnetic radiation
Radiation pressure from laser pointer, find force
Intensity of light passing through polarizer (law of malus)
Intensity of light before polarizer
Electric field after polarizer
Three polarizers
Solar stationary satellite, find area of solar sail
Multiple polarizers, find fraction of incident intensity
Laser powered sailing find time to reach % of speed of light from rest
id = !0
d"E
dt
id = !0 A dE
dt
!E = Emax sin kx !"t( ) y!B = Bmax sin kx !"t( ) z
k = 2# / $," = 2# f
!E ! d
!A"
!E # d!A = 0
!B ! d
!A"
!B # d!A = 0
Emax
Bmax
=$k= c " E
B= c
EB=
1µ0%0c
c = 1
µ0!0c"
1µ0!0
= 2.99 #108 m / s
c = ! f
!S =
1µ0
!E !!B
S =!S =
powerarea
!"#
$%& nstanteous
I = 1
cµ0
E2ms where E ms = Emax / 2( )
uE =12!0 cB( )2
, uB =1
2µ0
B2
uE =uB inelectromagnetic wave
F =!p!t
=IAc
I = !U / !tA
=c!pA!t
p =
Ic
and reflected : p =2Ic
I =powerarea
,then p =forcearea
=2Ic
! force = area "2Ic
I = 1
2cµ0
E2 =1
2cµ0
E0 cos!( )2= I0 cos2!
I0 =
1cµ0
E ms2 =
12cµ0
E02
E = E0 cos!
I1 =12
I0 , I2 = I1 cos2 45! 0( ) = 12
I0 cos2 45( )I3 = I2 cos2 90 ! 45( ) = 1
2I0 cos4 45( ) = I0 / 8
Fg = F p
F p = p A; p =2Ic
!"#
$%&
; Fg = GmmSun
d 2
2Ic
!"#
$%&= G
mmSun
d 2 ' A = GcmmSun
2Id 2
I X
I0
= cos2 !"( )( )X
2Ic
=FA!
FA=
2 P / A( )c
F =2Pc
= ma ! a =2PmC
v = at = %ic ! t = % " c2PmC
Chapter 31: Electromag. Waves
Chapter 32:Geometric OpticsLaw of rays Reflection l
Mirror image Full-length mirrorrequired length half the height o the person
Concave spherical mirrorMirror equation
Magnification Concave mirror
Always virtual, upright, and reduced image
Focal length of parabolic mirror
rd=
Rd + D !r = !i
do = di and h0 = hi
heightpe son !
heightpe son ! disteyes f omtop of head
2!
disteyes f omtop f head
2
C = R
f =R2
Case ype Direction Magnification
d <f Virtual Upright Enlarged
d=f Real Upright mage at infinity
f<d <2f Real Inverted Enlarged
d =2f Real Inverted Same size
d <2f Real Inverted Reduced
1d0
+1di
=1f
m = !
di
d0
=hi
h0
di =d0 f
d0 ! fd0 = +; f = !;di = !
f =
14a
where y(x) = ax2
ndex of refraction
law of refraction (Snellʼs Law
n =
cv
n1 sin!1 = n2 sin!2
nmedium =
sin!ai
sin!medium
where !ai > !medium
internal reflection
chromatic dispersionfirst rainbow appears 42 deg then 50 deg for second one outside first one
sin!c =n2
n1
(n2 " n1)
sin!c =1n
whenentering air
shadow of a ball
d + D =dRr
d 1!Rr
"#$
%&'= !D ( d =
DrR ! r
dligh bulb = d + D =Dr
R ! r+ D
imaged formed by a converging mirror
1d0
+1di
=1f
image produced : di =d0 f
d0 ! f
magnification : m =hi
h0
=!h0
di
d0
h0
displacement of light rays in transparent material
d = Lsin!d =t
cos!med um
sin !a "!med um( ) a
where !med um = sin"1 sin!a
n#
$%&
'(
opitcal fiber, max angle of incidence
!ai = sin"1 ncos sin"1 1
n#$%
&'(
#
$%&
'(#
$%
&
'(
Chap. 33: Optical Instr.
!B ! d!s = µ0"0
d#E
dt"$ + µ0ienc = µ0 id + ienc( )Lens-maker formula Lens equation
Convex lens Concave lensalways virtual, upright, reduced in sizeMagnification for lenses
Power of lens
myopia (near) image produced in front of retinahypermetropia (far) imaged produced behind the retinaCorrective lenses, find power
Microscopeobject to be magnified is placed just outside of foc length of the objective lensMicroscope magnification
telescope magnification
two positions of a convergin lens, find dist. between two positions
image produced by two lenses, find image produced by second lens with respect to sec. lens
image from the moon, find radius of the image of the moon on the screen
image produced by a lens and mirror, find mag.
1f= n !1( ) 1
R1
!1R2
"
#$%
&'
1f=
2 n !1( )R
1d0
+1di
=1f
Case ype Direction Magnification
f<d <2f Real Inverted Enlarged
d =2f Real Inverted Same Size
d >2f Real Inverted Reduced m = !
di
do
=hi
h0
D =
1mf
1!+
1"di
=1f= ____ diopeters
m = !
0 25Lfo fe
m! = "
!e
!o
= "fo
fe
1d0
+1di
=1f
;d0 = d ! di
1d ! di( ) +
1di
=1f
di + d ! di( ) = di d ! di( )f
df = did ! di2 " di
2 ! did + df = 0
x =d ± d 2 ! 4df
2
di 1 =d0 1 f1
d0 1 ! f1
di 2 =d0 2 f2
d0 2 ! f2
;d0 2 = d ! di 1
" di 2 =d ! di 1( ) f2
d ! di 1( ) ! f2
" di 2 =
d !d0 1 f1
d0 1 ! f1
#
$%
&
'(
#
$%
&
'( f2
d !d0 1 f1
d0 1 ! f1
#
$%
&
'(
#
$%
&
'( ! f2
di =d0 f
d0 ! f"
d0 fd0
= f
m = !di
d0
=hi
h0
# hi = !h0
di
d0
hi = !R fd
di 1 =d0 1 f1
d0 1 ! f1
di 2 =d0 2 f2
d0 2 ! f2
;d0 2 = d ! di 1
m1 =f1
f1 ! d0 1
;m2 =f2
f2 ! d0 2
m = m1m2 =f1
f1 ! d0 1
"
#$
%
&'
f2
f2 ! d0 2
"
#$
%
&'
( m =f1
f1 ! d0 1
"
#$
%
&'
f2
f2 ! d !d0 1 f1
d0 1 ! f1
"
#$
%
&'
"
#$
%
&'
"
#
$$$$$
%
&
'''''
Thin lens, find radius of curvature and thickness of edge of lens and how much thinner if made with high-index plastic
Chapt. 34: Wave OpticsSnellʼs Law for Hugyenʼs construction
Light traveling in an optical medium
placing object underw ater does not change color b/c freq is the same in both
constructive interference (in phase, difference is 2pi)
destructive interference (difference is pi)
double slit interference
Order of fringe (m)for constructive interferencem= give us angle of the first order of bright fringem=2 second order fringefor destructivem=0 gives us angle of the first order dark fringem= second order of fringefirst order is closest to central maximum
Constructive interference with small angle approx.
dist of bright fringes from central max.
dist of dark fringesdouble slit intensity on screen
single slit diffraction dark fringe
single slit intensity
thin film interference
color seen by thin film interference is wavelength that is interfering constructively
if n <n2, phase of the reflected wave will be changed by half a wavelengthif n >n2 then there w ll be no phase changeeven # of phase change same as no phase changeodd # of phase change is same as one phase change
min thickness that will produce const. interference
lens coating destructive interference
interferometer
can find thickness if we know its index of refractioncan find index of refraction if we know thickness
diffraction by a circular opening
intensity of interference pattern from double slits
two slit diffraction patern example, find interference fringe in central peak of diffr. envelope
diffraction grating
wavelength of monochromatic light
dispersion (diffraction grating)
resolving power
diffraction grating ex., find angle where first order max, and find angular sep. between wavelengths
diffraction on a crystal
width of central max.
CD as a diffraction grating
spy satellite, find minimum diameter of the lens
air wedge, find how thick is the film
n1 sin!1 = n2 sin!2
sin!1
sin!2
=v1
v2
=c / n1
c / n2
=n2
n1
!1
v1
=!2
v2
!n = ! v
c=!n
fn =v!n
=c / n! / n
=c!= f
!x = m" (m = 0,±1,±2...)
!x = m +
12
"#$
%&'( (m = 0,±1,±2...)
constructive !x = d sin" = m# (m = 0,±1,±2...)
destructive !x = d sin" = m +12
$%&
'()# (m = 0,±1,±2...)
when m = 0!" = 0!#x = 0bright fringe whichiscentral max.
d sin! = d y
L= m" (m = 0,±1,±2...)
y =
m!Ld
(m = 0,±1,±2...)
y =
m + 12
!"#
$%&'L
d (m = 0,±1,±2...)
E1 = Emax sin !t( )E2 = Emax sin !t + "( )E = 2Emax cos " / 2( )
IImax
=E2
E2max
I = 4Imax cos2 " / 2( )" =
#x$
2%( ) = 2%d$
sin&
I = 4Imax cos2 %dy$L
'()
*+,
asin! = m" (m = 1,2...)
position y =m"L
awherea = width
I = Imax
sin!!
"#$
%&'
2
where! =(a)
sin* =(ay)L
!x = m +12
"#$
%&'( = m +
12
"#$
%&'(a
n= 2t
m = 0,±1,±2...( ) where( =(a
n
tmin =
!ai
4n
m +
12
!"#
$%&
'ai
ncoat ng
= 2t m = 0,±1,±2...( )
Nmate ial ! Nai =
2tn"
!2t"
=2t"
n !1( )
sin! = 1.22"d#!R = sin$1 1.22"
d%&'
()*
where !R is the min. observable angular sep.
and d is the diameter of the lens
I = Imax cos2 ! sin""
#$%
&'(
2
where" =)a*
sin+ and ! =)d*
sin+
large distance " =)ay*L
and ! =)dy*L
1) asin! = " (m1 = 1)2) d sin! = m2"1)2)
=asin!d sin!
="
m2"
# m2 =da
N =Wd
d = distance, W=width, N= number of slits
d =1n
n = number of slits per unit length
d sin! = m" m = 0,1,2( )
! = sin"1 m#
d$%&
'()
m = 0,1,2...( )
di =d0 f
d0 ! f"
d0 fd0
= f
m = !di
d0
=hi
h0
# hi = !h0
di
d0
hi = !R fd
R =
!ave
"!= Nm where!ave # ! + ! + "!( )( ) / 2
d =WN
! = sin"1 m#d
$%&
'()
D =m
d cos!*! = D*#
2asin! = m" m = 0,1,2...( )
w = 2!y =
2"La
! = sin"1 #ai
d$
%&'
()
y =L
tan!
sin!1 1.22"d
#$%
&'(= tan!1 )x
h#$%
&'(
d =1.22"
sin tan!1 )xh
#$%
&'(
#
$%&
'(
2t = m +12
!"#
$%&' = m +
12+
12
!"#
$%&
m = # of bright fringes - 1extra 1/2because of dark fringe
Determining earth circumference, find how far North
Intensity of 2 polarizers, find angle between two polarizers
Throwing shadows, how far lightbulb away from wall
Partial linear polarization, find the fraction of light that is polarized
Solar sail problem, find max acc. of spacecraft and find velocity after certain time
Frequency of x-rays
Industrial laser, find RMS of E field and B field
Sirius star find distance in light years
Power of the sun radiation
Find total power incident and radiation pressure on roof
Convex mirror, find position and height of image
Neon laser in alcohol find speed, freq, and wavelength
d1
!1
=d2
!2
" d2 = !2( ) d1
!1
I = I0 cos2! =I0
2cos2!
! = cos"1 2II0
#
$%
&
'(
I0 goes down factor 2after1st polarizer
rd=
Rd + D
d 1!Rr
"#$
%&'= !D
( d =Dr
R ! r
d gh bu b = d + D =Dr
R ! r+ D
p =2Ic
=FA
FA=
2 P / A( )c
! a =2Pmc
v = at
f =
c!
RMSElect cField = cµ0 I
B =
Ec
d1light year
;1light year = 9.46i1015 m
Power = IAwhere A = 4!d 2
P = I 4!d 2( )
P = IA = I lw( )
p adiat on =
Ic
Area( ) = Ic
lw( )
1d0
!1di
= !1f
di = !1
1d0
+ 1f
;neg b / cbehind mirror
h1
d1
=h2
d2
! h2 =h1
d1
d2
nmedium =!o iginal
!medium
"!medium =!o iginal
nmed um
v = f !medium = f!o iginal
nmedium
#
$%
&
'(
nmed um =!o ginal
!medium
" !medium =!o g nal
nmed um
f =
c!
Iunpo = 2Im n
I po = Imax ! I ow
I o a = Iunpo + I po
polarized =I po
I o a
Eyeglass diopter, find if near or far-sighted and strength of of eyeglasses
Confining light in fiber, find max angle of incidenceTwo positions on converging lens, find distance
Power for reading newspaper
Focal length of magnifying glass given magnification
Farthest point w/o glasses given diopter
Find object distance and magnification to form certain image distance on right side of lens
Focal length of magnifying glass given object/image size
Three converging lens, find image
Near-sightedness
1d0
+1di
=1f= D
1d0
!1di
= D
D = n !1( ) 2
r+
n !1( )hnr 2
"
#$$
%
&''solve for r
tedge = center thickness + 2 rcu ve ! r 2cu ve !
wd ame e
2"
#$%
&'
2"
#
$$
%
&
''
D = n !1( ) 2rcu ve
+n !1( )h
nrcu ve2
"
#$$
%
&''solve for rcu ve
tedge new = center thickness + 2 rcu ve ! r 2cu ve !
wd ame e
2(
)*+
,-
2(
)
**
,
.tedge o d ! tedge new
tedge o d
sin!c =1n
!c = sin"1 1n
#$%
&'(
1d0
+1di
=1f
d0 + di = dbulb and sc een
di2 ! dbulb and sc eendi + dbu b and c een f = 0
solve using quadratic equationthen d i ! d0
1d0
+1d
=1f= D
both on same side, d is negassumed d0 is0.25m
1!+
1di
= D
di =1D
m! =dnea
f=
0.25mf
" f =0.25m
m!
1d0
+1di
=1f
1d0
=1f!
1di
" d0 =1f!
1d
#
$%&
'(
!1
d0 = 1!1d
#
$%&
'(
!1
wheredi iscoeff of _ f
m = !
di
d0
m! =hi
h0
m! =dnea
f
" f =dnea
hi
h0
1d0 1
!1
di 1
=1f" di 1 =
11f! 1
d0 1
di 2 =1
1f! 1
D ! di 1( )whered0 2 = D ! di 1
di 3 =1
1f! 1
D ! di 2( )whered0 3 = D ! di 2
False: he final image is on the left side of the third lens False: he final image is virtual False: he final image is upright True: he final image is inverted True: he final image is real True: he final image is on the right side of the
Separation of adjacent interference maximum
Minimum thickness of soap film
Number of lines in diffraction grating
Highest Order of diffraction grating
Distance you can resolve two objects
Cd diffraction, find spacing between tracks
Great wall from space, find angular size of the wall
Min angle human eye can resolve
Wavelength of laser beam in water of fish tank
double slit, determine the separation of the bright fringes
infrared filter, find minimum thickness
double slit, find size of individual slits and separation when given m
sep f int e fe ence max =!Ld
where L = screendistd = split sep
tmin thickness =
m + 12
!"#
$%&'
2n
sin! =m"d
# d =sin!m"
grating =1d=
m"sin!
a =m!
sin"#
1N
=m!
sin"
m =1
N!
slit width =
1.22 length( )!diam.
1.)! = arctandist.betweencd and screen
first dist.abovetable"#$
%&
2.)spacing =2(
sin!
sin!1 1.22"
diameter#$%
&'
arctan
widthaltitude
!"#
$%&
1 ) f =c
!in ai
2 ) !in wate =c
nf
d = w + s wherew = widthof slits, s = dist betweenslits
separation =m!L
d=
m!Lw + s
tmin =
!ai
4n
slit size =
!ilengthmimax defraction
separation =
!ilengthmax defraction
Enterprise, find length
Two ships in the night, find speed in c
Vulcan, find value of Lorentz factor beta.
Speed, how many times faster than fighter jet
Momentum, find KE
gold nuclei, find diameter when they reach certain total energy
Voyager, find how much pop of Earth aged during trip # of light years
Same Velocity, find KE to match proton beams
Transformation, find time in seconds
Redshift, find velocity of galaxy moving way
Black Hole, find Schwarzshild radius
Burger after the show, find usable energy
L = L0 1!vc
"#$
%&'
2
where v / c( ) is fractionof c
vsum =
v1 + v2
1+ v1v2
v =2!rT
" =vc=
2!r / Tc
1) v = !cms
"#$
%&'(
miles1609.34m
(3600s
hr
2) times faster =v
speed of jet
1) E = p2 + 0 9382
2) KE = E ! 0 938
gamma =given GeV
massof nucleon(ie 0 9315)
length =Lo
gamma
KE =
given MeVmassof proton
!massof electron
! = coeff of V
gamma =1
1" ! 2
t = gamma t "!xc
#$%
&'(
V =
c z2 + 2zz2 + 2z + 2
1000
r =2Gm
c2
whereG = gravitational cons tan t
m = 2 !1030 ! solar mass
E = mc2
Chapt. 35: RelativityPostulate 1 Law o physics are the same in each intertial reference frame, independent of the motion of this reference frame.Postualte 2 Speed of light is the same in every intertial reference frame. The speed of light (in vaccuum) is the ultimate speed.Time Dilation
Usually beta is very close to 0, and gamma is only slightly larger than Length contraction Frequency Shift
Upper signs are for observer and emitted signal moving away from each other, lower for moving toward each otherWavelength shift
Red shifted object moves away from usBlue shifted objects move toward us
Red shift
Relativistic velocity addition
Relativistic momentum
Energy contained in mass of particle at rest
Particle in motion
Kinetic energy
Momentum and energy
Speed, energy, momentum
Find total energy, KE, and momentum of electron with 99% of speed of c
Schwarzschild Raidus
Same velocity example, find required KE for electron beam with given proton beam KE
v / c = 0 9995
!t =!t0
1" v / c( )2= #!t0
! =vc=
pcE
" =1
1# ! 2=
1
1# v / c( )2
L =
v!t0
"=
L0
" f = f0
c ! vc ± v
! = !0
c ± vc ! v
z = !""0
=" # "0
"0
=c ± vc ! v
#1
for small v z ~ $
Lorentz
x ' = ! x " vt( )y ' = yz ' = z
t ' = ! t " vx / c2( )
Inverse
x = ! x '+ vt '( )y = y 'z = z 't = ! t '" vx '/ c2( )
objects move in opp.
v1+2 =v1 + v2
1+v1v2
c2
objects move in same
v1!2 =v1 ! v2
1!v1v2
c2
!p = ! m!v
E0 = mc2
E = ! E0 = ! mc2
K = E ! E0 = " !1( )E0 = " !1( )mc2
E = p2c2 + m2cAntimatter
E = ! p2c2 + m2cCase of zero mass (photons)E = pc
p =
!Ec
or E =pc!
E0 = mc2
! =1
1" # 2=
1
1" 0.992
E = ! E0
K = ! "1( )E0
p =#Ec
Rs =
2GMc2
Ke + mec2
mec2 =
K p + mpc2
mpc2
Ke = mec2
K p + mpc2
mpc2
!
"#
$
%& ' mec
2
( Ke = 0.511MeV( ) K p + 938MeV938MeV
!
"#
$
%& ' 0.511MeV( )