Changes in the syllabus content

Topic 1: Measurements and uncertainties Addition Deletion Rationale

1.1 Measurements in physics

Much the same, but SI units and fundamental and derived units from current syllabus section 1.2 are now in the new syllabus section 1.1.

1.2 Uncertainties and errors

Data booklet: Expression for fractional uncertainties in power equations Current syllabus section 1.2 “Measurements and uncertainties” is now named “Uncertainties and errors”. This was there implicitly in the previous guide, so the expectation is now much clearer.
Uncertainties can be expressed to both one significant figure and two significant figures. This now fits with current practice in scientific reports.
Determining the uncertainty in the gradient of a best straight-line graph should now make use of all the data point error bars. The uncertainty in the best straight-line gradient using the first and last data point error bars, that is, item 1.2.14, has been removed. Under the previous guide, the maximum and minimum lines were drawn ignoring many of the data points and error bars. This should help in obtaining more reasonable lines of best fit.
Topic 2: Mechanics Addition Deletion Rationale

2.1 Motion

Air resistance modified to fluid resistance.
Prescribed practical: Experiment to determine acceleration of free-fall Based on a review of many 4/PSOW forms these prescribed practicals are standard experiments carried out by many schools.
The experiments are generic and there is no need to carry out a specific task.
The introduction of experimental work being assessed in written examinations has necessitated the inclusion of such experiments.
Projectile motion has been added to the core, but the equation for range is not required. This brings together uniform horizontal motion and uniformly accelerated motion in one topic and allows students to apply their knowledge to a wider range of contexts.

2.2 Forces

Solid friction has been added, which includes the coefficients of static and kinetic friction. Current syllabus section 2.2 “Forces and dynamics” has been renamed. Momentum from section 2.2 has been moved to its own section in the new syllabus, section 2.4 “Momentum and impulse”. This includes expressions of Newton’s second and third laws. Solid friction has been reintroduced into IB physics as it was considered fundamental to have a quantitative approach to friction.

2.3 Work, energy and power

Equations for efficiency
The equation for elastic potential energy
Both allow for more quantitative work to be given and therefore a more complete overview of the energy topic.

2.4 Momentum and impulse

Old syllabus section 2.4 “Uniform circular motion” has been moved to section 6.1 in the new syllabus. The shuffling of topics means that all aspects of momentum can be taught as one unit.
Topic 3: Thermal physics Addition Deletion Rationale

3.1 Thermal concepts

Prescribed practical: Applying the calorimetric techniques of specific heat capacity or specific latent heat Molar mass and the Avogadro constant moved from old syllabus section 3.1 to new syllabus section 3.2. Heat capacities issues moved from old section 3.2 to new section 3.1.

3.2 Modelling a gas

A number of equations have been added to the core.
Prescribed practical: Investigate at least one gas law
The current syllabus section 3.2 “Thermal properties of matter” has been renamed in the new syllabus section 3.1. The addition of some equations allow for the mole, molar mass and Avogadro’s number to be given more relevance.
This allows for a more complete look at the kinetic model of an ideal gas, both qualitatively and quantitatively.
Topic 4: Waves Addition Deletion Rationale

4.1 Oscillations

Simple harmonic motion (SHM) is mostly qualitative. The definition of SHM with acceleration proportional to the negative of displacement remains. SHM has had most equations removed, except for period and frequency.
SHM energy, forced oscillations and resonance
To reduce SL content, the quantitative approach to SHM has been removed.

4.2 Travelling waves

Prescribed practical: Investigating the speed of sound The speed “v” in the current wave equations has been replaced by “c” in the new syllabus. The old syllabus section 4.4 has been moved into the new syllabus section 4.2 and called “Travelling waves”.

4.3 Wave characteristics

Amplitude and intensity
The inverse square law
Intensity equations
Polarization and Malus’s law
Polarization intensity
This allows for a more complete and unified approach to wave characteristics in the core rather than leaving part of the topic to AHL or standard level option.

4.4 Wave behaviour

Double-slit interference
Diffraction through a single slit
Prescribed practical: Determining refractive index
Reflection, refraction, diffraction and interference have been brought together into one topic.

4.5 Standing waves

Standing waves, boundary conditions, nodes and antinodes This is a natural extension to travelling waves and superposition.
Topic 5: Electricity and magnetism Addition Deletion Rationale

5.1 Electric fields

Solving problems with electron drift
Coulomb’s law (moved from the old syllabus section 6.2)

5.2 Heating effect of electric currents

Kirchhoff’s circuit laws for voltage and current
Real and ideal voltage and ammeters
Prescribed practical:
Investigating one or more factors that affect resistance
Changes will allow for a better understanding and application of electric circuits.

5.3 Electric cells

Primary and secondary cells.
Discharge characteristics of a simple cell
Prescribed practical:
Determining internal resistance
This topic now provides a strong link to chemistry.
Topic 6: Circular motion and gravitation Addition Deletion Rationale

6.1 Circular motion

Angular displacement and angular velocity Circular motion and Newton’s law of gravitation are naturally taught together.
Angular displacement and angular velocity are part of circular motion and allow for access to option B, which includes angular acceleration in rotational dynamics.
Topic 7: Atomic, nuclear and particle physics Addition Deletion Rationale

7.1 Discrete energy and radiation

Quantitative approach to transitions of electrons between energy levels
Prescribed practical: Investigating half-life
Natural inclusion which helps to explain a number of observable phenomena.

7.3 The structure of matter

Particle physics, including quarks, leptons, antimatter, conservation laws, exchange particle, Feynman diagrams and more.
Lots of new information in the Physics data booklet to reflect this addition.
This is modern and important physics, and it was felt that all physics students should have an insight into particle physics.
Material mostly from the old option D.
Topic 8: Energy production Addition Deletion Rationale

8.1 Energy sources

Specific energy has been added to energy density. Some equations have been removed.
Degraded energy has been removed from this section.
World energy sources have been removed as well as some other section 8.2 and 8.3 items.
A large reduction in content here reduces some of the load from the core material.

8.2 Thermal energy transfer

Conduction, convection and radiation are explicit here. Much of the detail of 8.4 and 8.6, such as the coefficient of volume expansion
Surface heat capacity
Much of the same greenhouse effect material, but less detail is now required.
As in section 8.1, there is a reduction in the emphasis on climate change to free up more time in the teaching of the core material.
Topic 9: Wave phenomena (AHL) Addition Deletion Rationale

9.1 Simple harmonic motion

SHM equations now include the pendulum and mass on a spring. Most of the SHM equations from the core have been moved to the new SHM in AHL. Simple pendulum and mass on a spring are common experiments, so they can now be formally studied.
The core material for SHM has been reduced, leading to the material moving to AHL.

9.3 Interference

Expanded syllabus content and new equations in the Physics data booklet
Prescribed practical: Young’s double-slit
Topics incorporated from the old option G to make a more coherent approach to the topic.

9.4 Resolution

One new resolution equation in the Physics data booklet Polarization Polarization has been moved to the core section of the guide.
Topic 10: Fields (AHL) Addition Deletion Rationale

10.1 Describing fields

10.2 Fields at work

New equations made more explicit
Topic 11: Electromagnetic Induction (AHL) Addition Deletion Rationale

11.2 Power generation and transmission

Diode bridges, half-wave and full-wave rectification
Prescribed practical: Diode bridge rectification circuit
Some details on transformers Slight increase in the depth of knowledge for this topic to provide a more complete understanding of power transmission.

11.3 Capacitance

Capacitance and dielectrics
Capacitors in series and parallel
Resistor-capacitor series circuits and the time constant
New Physics data booklet equations
Capacitors play an important part in many areas of physics so a basic introduction is given in the new guide.
Physics data booklet additions are used to support the syllabus changes.
Topic 12: Quantum and nuclear physics (AHL) Addition Deletion Rationale

12.1 The interaction of matter with radiation

Photons
The photoelectric effect
Matter waves
Pair production and pair annihilation
Quantization of angular momentum in the Bohr model for hydrogen
Tunnelling, potential barrier and factors affecting tunnelling probability
Some material gathered from option topics and other topics added to provide a more coherent approach to this topic.

12.2 Nuclear physics

Rutherford scattering and nuclear radius The changes make this topic more explicit in the syllabus.

Options

The four option topics are largely new and so a comparison with previous option topics is not feasible. There is new content in all topics to ensure they are up to date. Teachers are encouraged to look at each of the topics and decide which ones will best match the needs and interests of their classes.

Changes to external assessment

There are some changes to the examination papers. These are summarized below.

  • The weighting of the assessment objectives for paper 1 has changed so that 50% of the paper will address objective 3.
  • Assessment of NOS may be incorporated into any of the questions within the three examination papers.
  • In paper 2 there will no longer be any choice of question. As a result there will no longer be section A and section B. Students will answer all questions
  • In paper 3 there will be two sections: in section A, students will answer data-based questions and in section B they will choose questions on one of the options.