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IB Physics SL - Study Guide
Science Skills
List the seven fundamental base units and their abbreviations:
Unit Abbreviation
Length Meter m
Mass Kilogram kg
Time Second s
Electric Current Ampere A
Temperature Kelvin K
Amount of Substance Mole mol
Luminous Intensity Candela cd
Metric Prefixes – List the unit prefixes in their appropriate decimal position
Dimensional Analysis
Convert the following:
20 mi hr
→ m s
×
×
×
− 1
0.0 007 km
2
→ m
2
2
×
1000 𝑚
1 𝑘𝑚
×
1000 𝑚
1 𝑘𝑚
2
or 0. 0007 𝑘𝑚
2
× (
1000 𝑚
1 𝑘𝑚
2
2
Determine the units for Q:
Q = mc ΔT
− 1
− 1
m (mass) kg
c (specific heat) J kg
K
ΔT (change in temp) K
Motion
Scalar Vector
How far (m) Distance Displacement
How fast (m s
) Speed Velocity
Displacement vs Time Velocity vs Time Acceleration vs Time
Meaning of the
Graph
Slope:
Velocity
Slope: Acceleration
Area under the Curve:
Displacement
Area under the Curve:
Velocity
Constant
Displacement
Constant
Positive
Velocity
Constant
Negative
Velocity
Constant
Positive
Acceleration
(speeding up)
Constant
Negative
Acceleration
(slowing down)
Forces
Type of Force Variable Description/Important Properties Equation
Weight
F
g
Force of gravity on an object with mass
F
g
= mg
Tension
F
T
Always pulls in the same direction as the
rope or chain providing the tension
Normal
Reaction
R
Always perpendicular to a surface
Friction
F
f
Always opposes the motion of an object
F
f
= μR
Air Resistance
F
air
Increases with surface area and velocity
If an object has a net force of zero its motion is either:
Not moving (velocity = 0 m s
) or Moving at a constant velocity
Newton’s Laws
Newton’s
First Law
A object at rest remains at rest and an object in motion remains in motion
until and unless an external force acts upon it (Unbalanced force).
Newton’s
Second Law
The rate of change of momentum of an object is proportional to the
resultant force acting on the body and is in the same direction. (F = ma)
Newton’s
Third Law
All forces occur in pairs. Every action has an equal and opposite reaction
Data Booklet
Equations:
Variable
Symbol
Unit
Force
F N
𝐹 = 𝑚𝑎
Mass
m kg
𝐹
≤ 𝜇
𝑅
Acceleration
a m s
𝐹
= 𝜇
𝑅
Normal Reaction Force
R N
Coefficient of Kinetic Friction
d
Coefficient of Static Friction
s
Terminal Velocity
The maximum velocity a falling body can achieve. This occurs when the
force of air resistance is equal and opposite to the weight and F net
= 0 N.
Circular Motion
Variable
Symbol
Unit
Draw in
vectors
for v, a c
and F c
Distance d m
Angular Distance
θ rad
Angular Velocity
ω rad s
Data Booklet Equations:
Linear Velocity
v m s
Centripetal Acceleration
a m s
𝑣
2
𝑟
4 𝜋
2
𝑟
𝑇
2
Centripetal Force
F
c
N
𝑚𝑣
2
𝑟
2
Defining Circular Motion
Period T s
Angular Velocity ω rad s
Time per revolution
Vertical Circular Motion
Top: Bottom:
F
net
= F
c
= F
T
+ F
g
F
net
= F
c
= F
T
Top: Bottom:
F
net
= F
c
= F
g
= F
c
= R - F
g
Circular Motion with Friction and Angles
Relationships between variables:
𝐹
𝑓
= 𝐹
𝑔
𝐹
𝑐
= 𝑅
Relationships between variables:
𝑅 = 𝐹
𝑔
𝐹
𝑐
= 𝐹
𝑓
Relationships between variables:
𝑇
𝑦
= 𝐹
𝑔
𝐹
𝑐
= 𝑇
𝑥
Calculating Power
In terms of work and time:
𝑃𝑜𝑤𝑒𝑟 =
𝑊𝑜𝑟𝑘
𝑇𝑖𝑚𝑒
In terms of force and velocity:
𝑃𝑜𝑤𝑒𝑟 = 𝐹𝑜𝑟𝑐𝑒 × 𝑉𝑒𝑙𝑜𝑐𝑖𝑡𝑦 = 𝐹𝑣
Units
Standard Unit From Equation Fundamental SI Units
Work
J N m kg m
s
Power
W J s
kg m
s
Types of Energy
Kinetic Energy Elastic Potential Energy Gravitational Potential Energy
𝑚𝑣
𝑘∆𝑥
𝑚𝑔∆ℎ
Conservation of Energy
Total Energy Before = Total Energy After
Work-Energy Theorem
Work → Energy Energy → Work
𝐹𝑠 =
1
2
𝑚𝑣
𝑚𝑣
= 𝐹𝑠
Momentum
Variable
Symbol
Unit
Data Booklet Equations:
Momentum p
kg m s
Mass m
kg
Velocity v m s
Time t s
𝐾
2
Kinetic Energy E K
J
Impulse Impulse N s or kg m s
Conservation of Energy Problems
“Explosion”
p AB
= p A
“Hit and Bounce”
p A
= p A
“Hit and Stick”
p A
= p AB
Waves – Sound
Variable
Symbol
Unit
Data Booklet Equations:
Period T s
Frequency
f Hz
Wavelength
λ m
Amplitude
A m
Wave Speed
v m s
Simple Harmonic Motion Graphs
Velocity vs Displacement
Accel. vs Displacement
Types of Waves Picture Definition Examples
Transverse
Particles move perpendicular
to the motion of the wave
- Light
- Ripples in a Pond
- Earthquakes
Longitudinal
Particles move parallel
to the motion of the wave
Parts of a Wave
Label the Wave:
- Amplitude
- Wavelength
- Crest
- Trough
Harmonics
Open Pipe Closed Pipe String
End Conditions Antinode Antinode Node Antinode Node Node
3
rd
Harmonic
L =
3
2
λ L =
5
4
λ L =
3
2
λ
2
nd
Harmonic
L = 1 λ L =
3
4
λ L = 1 λ
1
st
Harmonic
(Fundamental)
L =
1
2
λ L =
1
4
λ L =
1
2
λ
Interference
Constructive Path Difference = n λ Destructive Path Difference = ( n + ½) λ
When 𝜃
= 𝜃
𝜃
= 90°
𝜃
= 𝑠𝑖𝑛
(
𝑛
𝑛
)
Reflection
Law of Reflection
Angle of Incidence = Angle of Reflection
Polarized Light
𝐼 = 𝐼
𝑐𝑜𝑠
𝜃
I
Intensity Observed
I
0
Original Intensity
Difference in Angle
Double Slit Experiment
𝑠 =
𝜆𝐷
𝑑
Label this diagram:
s
Distance between fringes
λ Wavelength
D
Distance to Screen
d
Distance between slits
Electricity
Charge Current
Symbol q Unit Coulombs [C] Symbol I
Unit Amperes [A]
Charge of 1 Electron 1.6 × 10
C
Unit in terms of Coulombs A =
C
s
of Electrons per Coulomb 6.25 × 10
18
e
Drift Speed
Variable
Symbol
Unit
Data Booklet Equation:
Current I A
I = nAvq
of Electrons per m
3
n ---
Cross Sectional Area A M
2
Drift Speed v m s
A = πr
Charge q C
Electrical Properties
Property What is it? Symbol Unit
Voltage Potential Difference V
Volts [V]
Current The rate at which charges move through a wire I
Amperes [A]
Resistance
How hard it is for a current to
flow through a conductor
R
Ohms [Ω]
Kirchhoff’s Laws
ΣI = 0 (junction) ΣV = 0 (loop)
The total current coming into a junction must equal the
total current leaving the same junction
The sum of the voltages (potential differences) provided
must equal the voltages dissipated across components
Across resistors Always Negative
Entering Junction → ●
Positive Negative to Positive →
Positive
Exiting Junction ● → Negative Positive to Negative → Negative
Power
In terms of V and I In terms of I and R In terms of V and R
P = V × I P = I
2
R
P =
V
2
R
Voltage Dividers
Light-Dependent Resistor Thermistor
Symbol
Relationship
Light Increases Heat Increases
Resistance Decreases Resistance Decreases
Circuit
Switch turns on in the dark: Switch turns on in a fire:
Batteries
Primary Cells Secondary Cells
Cannot be recharged
Can be recharged by passing a current
through the battery in the opposite direction
as it would normally travel
Variable
Symbol
Unit
Data Booklet Equation:
Electromotive Force (e.m.f) ε V
ε = I(R + r)
Current I A
Circuit Resistance R Ω
Internal Resistance r Ω
Force Fields
Forces between objects
Coulomb’s Law
Variable
Symbol
Unit
Data Booklet Equations:
Electrostatic Force F N
1
2
2
Object 1 Charge q 1
C
Object 2 Charge q 2
C
0
Separation Distance r M
Coulomb Constant k N m
2
C
k = 8.99 × 10
9
N m
2
C
Permittivity of Free Space ε 0
C
2
N
m
ε 0
= 8.85 × 10
C
2
N
m
Universal Law of Gravitation
Variable
Symbol
Unit
Data Booklet Equation:
Gravitational Force F N
2
Object 1 Mass M kg
Object 2 Mass m kg
Separation Distance r m
Gravitational Constant G N m
2
kg
G = 6.67 N m
2
kg
Force Fields
Electric Field Gravitational Field
Symbol E
Data Booklet Equation:
𝐹
𝑞
Symbol g
Data Booklet Equation:
𝐹
𝑚
𝑀
𝑟
2 Units F C
