Title: REGENTS PHYSICS
1REGENTS PHYSICS
2(No Transcript)
3MEASUREMENTS
- SCALARS
- Magnitude Only
- Distance
- Speed
- Mass
- Time
- Charge
- VECTORS
- Magnitude Direction
- Displacement
- Velocity
- Acceleration
- Weight
- Force
- Momentum
- Gravitational Field
- Others
4Vector Addition
3 m/s
f
4 m/s
R 5 m/s
3 4 5
5Vector Components
Fx F cos f
F
Fy
Fy F sin f
f
Fx
6Accel down Inclined Plane
y
a
gx
gx g sinQ
Q
gy g cosQ
g
x
gy
Q
gx
7Distance vs. Time Graph
Slope Dd/Dt
velocity
distance
Average Velocity
do
time
8Velocity vs. Time Graph
Slope Dv/Dt
acceleration
accel 0
Constant
velocity
vo
time
9Velocity vs. Time Graph
Area Ddistance
Dd A1 A2
AREA 2
vo
velocity
AREA 1
time
10Motion Detector
111.
12KIMEMATICS EQUATIONS (L3)
Vf Vi at
d Vit ½ (at2)
Vf 2 Vi2 2ad
13NEWTONS LAWS OF MOTION
- FIRST LAW INERTIA
- an object at rest tends to stay at rest...
- Unless acted upon by some outside force
- once moving will keep on moving with a constant
velocity - speed and direction
14INERTIA
Tendency to resist motion or a change in motion
Inertia a mass
15Newtons Second Law
a a F
a
F
m
m
2a
2F
m
m
16Newtons Second Law
a a 1/m
a
F
m
m
1/2 a
2m
2m
F
17UNIT OF FORCE NEWTON (N)
F ma
Units?
N (kg)(m/s2)
18EQUILIBRIUM
If
Then
SF 0
a 0
19a a 1/m
a a F
a a F/m
The acceleration of a known mass is used to
define a force.
a F/m
20 F ma
a 1 m/s/s
Applied F
If m 1 kg
Applied F 1 Newton (N)
21MASS VS WEIGHT
Mass (m) How much stuff (matter)
Weight (W) (Fg) Force exerted on object by
gravity
Fg a m
22MASS vs WEIGHT
2m
Fg mg
m
g 9.8 N/kg
Fg
gravitational field constant
g
CONSTANT
m
23g gravitational field constant
g force
mass
(kg)(m/s2)
(m/s2)
N
kg
kg
acceleration !!!
g 9.8 N/kg
g 9.8 m/s2
24g of Planets
25Newts Third Law
- For every action, there is an equal but opposite
reaction
F12 - F21
26KINETIC FRICTION
m
Ff
CONSTANT
N
m coefficient of friction
Ff mN
27(No Transcript)
28Work Defined
F
m
m
d
Work Force . Distance F . d cos q
q angle between F and d vectors
If q 0
Then cosq 1
29Work F d cos q
Work DKE
KE ½ mv2
30GRAVITATIONAL POTENTIAL ENERGY
DPEg mgDh
31Energy Units
Joule (J)
N m
32HOOKES LAW
F kx
33FORCE VS STRETCH
F a DL
F
k
constant
slope
DL
FORCE (N)
k spring constant
(N/m)
k F/DL
STRETCH (m)
34Potential Energy Stored in Springs
PE spring ½ kx2
35Power
- Rate at which work is done
P work/time
P D Energy/time
J/s
Watt
36Power
- Rate at which work is done
P work/time
(
)
P Force x distance / time
distance / time speed
P F v
37Centripetal Acceleration
- Center Seeking, toward center of circle
Caused by Force in same direction
ONLY CHANGE DIRECTION, NOT SPEED
Centripetal Force (Fc)
Fc do NO WORK
38F ma
Fc mac
ac v2/r
Fc mv2/r
39Gravitational Force
Fg Gm1m2
d2
Universal
40Momentum (p)
p (m) (v)
- Momentum is a Vector
- Direction of momentum same as velocity
41IMPULSE (J)
J
F
Dt
IMPULSE
Dp
F
Dt
Dp
J
N s kg m/s
42ELECTROSTATICS
43Coulombs Law
k
Fe Q1 Q2
r 2
k electrostatic constant
k 9.0 x109 Nm2/C2
44Potential Difference
V Work Charge
V energy per unit of charge
Volt Joule / Coulomb
Energy DV (Charge) DV q
45A Different Look atElectric Fields
DV
E
Dd
Electric Field Gradient (V/m)
Electrical topography
46Electric Field
- Two ways to think about it
DV /Dd
Fe /q
(V/m)
(N/C)
47ELECTRIC CIRCUITS
48Electrical Current (I)
- Measure of Rate of Flow of charge
Current flow
1 Amp 1 Coulomb
second
49Electric Current (I) (amps)
1 Amp 1 Coulomb
second
50RESISTANCE vs. TEMP
51RESISTANCE
R vs Temperature
DR a DT
(SEE IP SIM)
52RESISTANCE
R vs LENGTH ( l )
R a l
53RESISTANCE
R vs X-SECTION AREA (A)
A
A
R a 1/A
54RESISTANCE
R r l / A
r RESISTIVITY
55(No Transcript)
56Electrical Circuits
ammeter
R
power supply
-
resistor
I
voltmeter
Ammeter connected in series
Voltmeter connected in parallel
57(No Transcript)
58Ohms Law
I a DV
DV
R
(RESISTANCE)
I
UNIT OF RESISTANCE IS OHM (W)
DV IR
59Series Circuit
IT I1 I2 I3 .
DVT DV1 DV2 DV3 .
60SERIES RESISTORS
IT I1 I2 I3 .
DVT DV1 DV2 DV3 .
61PARALLEL CIRCUIT
IT I1 I2 I3 .
I DV /R
DVT DV1 DV2 DV3 .
THE MORE RESISTORS, THE LESS THE RESISTANCE!
62Parallel Circuit
63Parallel Circuit
IT I1 I2 I3
DVT DV1 DV2 DV3
64SERIES CIRCUIT
IT I1 I2 I3 .
DVT DV1 DV2 DV3 .
DV IR
RT IT R1 I1 R2 I2 R3 I3 .
RT R1 R2 R3 .
RESISTANCE ADDS UP!
65Combo Circuit
DV2 DV3
66(No Transcript)
67P IDV
66m
56m
68ELECTRICAL POWER
P I DV
P I2R
DV IR
P I DV
P DV2/R
I DV /R
69ELECTRICAL POWER
P I DV
P I2R
P DV2/R
70MAGNETIC FIELDS
71Magnetic Fields (B)
- Charges in motion create magnetic fields (B
fields) - Exert forces on other moving charges (currents)
72SOLONOID RIGHT-HAND RULE
S
N
I
Fingers Current Thumb N Pole
73Right Hand Rule B of Straight Wire
Thumb Current Fingers B Flux
74Straight Wire B (overhead view)
B field FLUX
wire
Current (out of page)
75RHR FB on I or q
Thumb Current Fingers B Flux Palm Force
76Magnetic Forces on Moving Charges
FB is Fc
v
FB a q
q
FB a B
FB
r
77MECHANICAL WAVES
78WAVE VELOCITY
v distance/time
v wavelength/period
T 1/ f
v l / T
v l f
79v l f
(medium dependent)
(source dependent)
l a v
(Demo Oscil)
80DOPPLER EFFECT
(see film-loop)
81OPTICS
82Law of Reflection
Qi Qr
N
Qr
Qi
83Fast to Slow
Slow to Fast
N
Qi
Qi
fast
slow
slow
fast
Qr
refracted ray bends toward N
refracted ray bends away from N
Qr
84(No Transcript)
85Index of Refraction (n)
(speed of light in vacuum)
(speed of light in a given medium)
c 3.0 x 108 m/s
The bigger the n value, the slower the light
travels.
86(No Transcript)
87Snells Law Proof
n2
n1
V a l
n1 sin Q1 n2 sin Q2
88Total Internal Reflection
89DIFFRACTIONDOUBLE SLIT
S1
S2
BARRIER
BARRIER
BARRIER
SCREEN
90Diffraction vs. Wavelength
LONG l
SHORT l
91Electromagnetic Spectrum
l in vacuum
f is constant, Does not D with speed
92(No Transcript)
93Electromagnetic SpectrumVisible Light
400 500
600 700
Wavelength (nm)
94QUANTUM MECHANICS
- PHOTOELECTRIC EFFECT
- COMPTON EFFECT
- DeBROGLIE (MATTER) WAVES
95Light Energy Quantized
E hf
96Light Energy Quantized
v lf
E hf
v c
E hc
hc constant
l
hc 1.24 x103 eV nm
hc 1.99 x10-25 Jm
97Mass - Energy Equivalence
UNIT CHECK!
E mc2
1 kg 9 x 1016 J 9 x 107 GJ !!
1 amu 1.5 x 10-10 J 931 Mev
98ATOMIC PHYSICS
99Balmer Series
Hydrogen Emission Spectra
H atom energy levels
(eV)
e
e
e
e
100Ephoton Ei - Ef
Ephoton 13.6 3.4
Ephoton 10.2 eV
101(No Transcript)
102NUCLEAR PHYSICS
NUCULER
103NUCLEUS
- NUCLEAR PARTICLES (NUCLEONS)
ATOMIC MASS NUCLEONS
A
n
4
X
He
n
Z
2
ATOMIC PROTONS
104Mass - Energy Equivalence
E mc2
1 amu 1.6606 x 10 27 kg
1 amu 1.5 x 10-10 J 931 Mev
1 amu 931 Mev
105235U FISSION
106NUCLEAR FUSION SUN
107NUCLEAR FUSION (LLE)
Dm .018 amu 17 Mev
ENERGY/NUCLEON 3.4 Mev
108Particle Physics
109(No Transcript)
110Particle Physics
- Fundamental Particles
- Hadrons
- Baryons Made of 3 Quarks
- Protons (uud)
- Neutrons (udd)
- Mesons Made of 2 Quarks
- Bound pair quark-antiquark
- Leptons fundamental particles/antiparticles
- Electron Electron neutrino
- Muon Muon Neutrino
- Tau Tau Neutrino
111u
u
d
u
d
d
112GOOD LUCK!!
?