International Baccalaureate Physics


The material that follow are reproduced with the permission of the International Baccalaureate Organization


INTERNATIONAL BACCALAUREATE (IB)


Nature Of The Subject 

Physics is the most fundamental of the experimental sciences in that it seeks to explain
the basic features of the natural world primarily in terms of the interactions between
matter and energy. It presumes to describe the world using such elementary (but not
always intuitive) concepts as mass, time, distance, charge, as well as more subtle
constructions such as momentum, force energy, field, waves, and the surprising aspects
of relativity (special and general) and quantization (of mass – atoms and particles,
charge, and energy). There is the technological side of physics that complements this
purely conceptual view, in which physical principles have been applied to construct
various devices and machines that have affected the daily lives of all human beings, and
also of course, to expand the boundaries of physical knowledge itself.

Physics is an organized body of knowledge. It is also a uniquely human activity. These
are not easily separable parts, since it is the activity that produces and organizes the
body of knowledge, and this understanding in return re-stimulates the process that
expands knowledge. It is a dynamic thing that grows and shapes itself over time. In an
educational setting we often try to assess the students’ understanding of the body of
scientific knowledge by the success in describing or applying portions of it. This can often
be carried out using examinations, tests and assignments.


Physics as a process is really a combination of complementary activities. The first
approach is theoretical, in which abstract models such as analogues or mathematical
systems are formulated to formalize phenomena and to make predications for a variety
of circumstances. The other tactic is experimental, in which we link these abstract
concepts to reality itself through controlled manipulation and careful observation. 
Sometimes, of course, rather than testing against deductions of a model, the experiment
is used to inductively create the model; In any case, tit is the experimental work that
separates science from pure mathematics or philosophy. The survival of a model rests
on its precision and utility in the explanation and prediction of experimental results. To
assess student success in learning the process of science, teachers must observe
students doing science. Students need to be given the opportunity to hypothesize,
design and carry out investigations, and theorize models.


What must not be forgotten in this discussion of both the knowledge and the process of
doing physics is the evolution of the societal impact of physics and one of the best ways
to explore this is by illuminating its historical development. This can place the knowledge
and the process in a context of dynamic change rather than the static picture of the
world according to physics that far too many students perceive. Additionally, this can
give students insights into the human side of physics: the individuals, their personalities,
their times and social milieu, their challenges, disappointments, and triumphs. Examining
physics with this context in mind can enhance student appreciation of the impact of
physics on the societies of he past and present, enabling informed speculation about the
future.

Physics as an experimental science

Early in the history of science physicists were both theoreticians and experimenters –
natural philosophers. The body of scientific knowledge has grown in size and complexity
and the tools and skills of theoretical and experimental physicists have become so
specialized that it is difficult (if not impossible) to be highly proficient in both areas. While
students should be aware of this, they should also know that the free and rapid interplay
of theoretical ideas and experimental results in the public scientific literature maintains
the crucial links between these fields. At the school level all students should undertake
both activities. Theory and experiments should complement one another naturally, as
they do in the wider scientific community. In the IB physics programme there will often
be a rapid shift between theoretical and experimental work during the study of many
topics. 

The experiment can be thought of as a boundary between the complicated, dirty real
world and the clean conceptual models that we use to describe the world. The models
are created through abstraction, pattern recognition and induction, augmented by
deduction. They link concepts by definite laws and special relationships that form the
framework of our understanding of the way the world works. We use deductive and
predictive qualities of the model to suggest how some phenomenon in the real world will
play itself out. The experiment usually focuses on some small portion of the real world
and its associated models. A phenomenon is observed, a model is constructed, a
prediction is made, the experiment is carried out, adjustments may be made to the
model, and the sequence is repeated. Of course, it is never quite that simple! The key
element of this paradigm is the checking of our conceptual understanding of the world
with the world itself. This feature alone sets experimental sciences apart from other
approaches to knowledge.

I would like to specially thank Pat Adams, the Publications Manager of the International
Baccalaureate Organisation for allowing me to use the above extract about the 'Nature
of the Subject' and sections of the "Syllabus Details" reproduced below from the Physics
Guide. 


While every effort has been made to type this material carefully, I shall be pleased to
rectify any errors that have inadvertantly crept in. Please remember that the what
follows from the SYLLABUS below will APPLY FOR EXAMINATIONS up TO NOVEMER 2002 only.


Topic 1 – Measurement

 

1.1   Standards of Measurement

1.1.1        Distinguish between and give examples of fundamental and derived                   units.  

1.1.2        Define and use the terms ‘ kilograms’  ‘metre’ and ‘second’

1.2          Vectors and Scalars

1.2.1        Distinguish between and give examples of vector and scalar                   quantities

1.2.2        Represent vectors by directed line segments and add subtract                   co-planar vectors by the graphical method.

1.2.3        Multiply and divide vectors by scalars.

1.2.4        Resolve a vector into perpendicular components, and apply this                   technique in vector problem solving, by adding co-planar components,                    and by recombining components into a resultant vector.

1.3  Graphical techniques

1.3.1       Use experimental or given data to provide a set of ordered pairs of                  numbers, choose appropriate linear scales, plot the points with                  uncertainty bars, and draw a ‘best-fit’ line. 

1.3.2       Measure and interpret the significance of the slope (gradient),                  intercepts and area under a graph with linear scales and derive the                  corresponding units.

1.3.3       Apply given transformations of powers and reciprocals to data so as                  to produce linear graphs.

1.3.4       Match the generic graph of y=mx+c, where m and c are constants,                  and determine m and c. 

1.3.5       Measure and interpret sinusoidal graphs, and determine amplitude,                  and frequency, period or wavelength. 

1.3.6       Use experimental or give data to produce and draw a frequency                  histogram, choosing an appropriate bin (or interval) width, and                  interpret patterns in the plotted data.

1.4          Uncertainties and errors 

1.4.1       Distinguish between and give examples of, uncertainties due to lack                  of precision and errors due to lack of accuracy.

1.4.2       Describe, distinguish between and give examples of, random                  uncertainties and systematic errors

1.4.3       Record, along with the raw data obtained in experimental                       measurements, the uncertainties in those data (analogue or                  digital services)

1.4.4       Qualitatively describe how the effects of random uncertainties may be               reduced by repeating measurements and by using graphs.

1.4.5       Describe how large uncertainties can result from finding the small               difference between two large numbers, and from squaring or cubing a               number.

Topic 2 – Mechanics

2.1   Kinematical concepts

2.1.1       Define the terms ‘displacement’, ‘velocity’ and ‘acceleration’ and                  identify them as vector quantities.

2.1.2       Describe an object’s motion from more than one frame of reference.

2.1.3       Interpret and sketch position-time graphs, velocity-time graphs and                  acceleration-time graphs. 

2.1.4       Define and distinguish between the terms ‘instantaneous velocity’               and ‘average velocity’ and ‘instantaneous acceleration’ and ‘average                  acceleration’.

2.1.5       Given a position-time graph, calculate the average velocity over a time               interval and the instantaneous velocity at a given instant.

2.1.6       Given a velocity-time graph, calculate the instantaneous acceleration               at a given instant, the average acceleration over a time interval and               the displacement over a time interval.

2.2   Linear motion with constant acceleration

2.2.1       Derive and apply the appropriate equations for uniformly accelerated                  motion to solve problems.

2.2.2       Calculate velocity and acceleration from simple timing situations                  involving uniformly accelerated motion. 

2.2.3       Identify and describe the acceleration of a body in free fall, and state               that free fall acceleration is independent of mass.

2.3    Concepts of force and mass

2.3.1       Describe force as the cause of velocity change or deformation.

2.3.2       Identify the forces acting on an object, and draw free body diagrams.

2.3.3       Define and distinguish between the terms ‘mass’ and ‘weight’

2.4   Newton’s first law of motion

2.4.1             State, and identify and construct examples of, Newton’s first law of       motion.

2.4.2          Apply SF = 0 as the condition for translational equilibrium.

2.5      Newton’s second law of motion

2.5.1             Determine the resultant force from a free body diagram. 

2.5.2            Identify initial mass as the ratio of resultant force to acceleration

2.5.3            State and identify and construct examples of, Newton’s second law of       motion, and apply the law to problems involving constant forces.

2.6  Newton's third law of motion

2.6.1            State and identify and construct examples of, Newton’s third law of        motion. 

2.6.2         Apply Newton’s third law of motion to everyday experiences.

2.7      Projectile, simple harmonic and uniform circular motion

2.7.1         State the independence of the horizontal and vertical motion of a          projectile.

2.7.2         Solve simple problems on projectile motion, neglecting air resistance.

2.7.3         State that the trajectory of projectile motion is parabolic.

2.7.4         Describe and construct examples of physical systems oscillating with         simple harmonic motion (SHM)

2.7.5            Identify the points in the motion of an oscillating mass on a spring or a      simple pendulum where the acceleration and velocity are zero, and        where they achieve their extreme values.

2.7.6        Explain why a body moving with uniform circular motion must be regarded as               undergoing acceleration, state the direction of the acceleration, and define            centripetal force and centripetal acceleration.

2.8       Linear momentum

2.8.1          Define the terms ‘momentum’ and ‘impulse’ and demonstrate an understanding of their     vector nature.

2.8.2          Use Newton’s second law of motion in the form “Force is the rate of change of the        linear momentum of a body to derive Fnet = ma.

2.8.3          Describe and identify situations involving the conservation of linear momentum,           including elastic and inelastic collisions and explosions.

2.8.4          Solve problems, involving one-dimensional interactions.

2.9       Work, energy and power

2.9.1          Describe the relationship between work done and energy transferred.

 

2.9.2          Calculate the work done on a body by a constant force.

2.9.3          Define the term ‘potential energy’.

2.9.4          Calculate changes in gravitational potential energy in a uniform field, and describe        changes in elastic potential energy in a material.

 

2.9.5           Define and calculate ‘kinetic energy’.

2.9.6           List different forms of energy and give examples of the transformation of energy from     one form to another.

2.9.7          State the principle of conservation of energy and apply it to mechanical situations.

2.9.8          Define the term “power”, state its units and solve associated             problems.                                                                                                              

Topic 3 – Thermal Physics And Properties Of Matter 

3.1 The atomic model of matter and states of matter

3.1.1       Describe the four states/phases of matter and their macroscopic                  properties, relating these to the microscopic terms.

3.1.2       Describe and explain changes of state with temperature in                   macroscopic and microscopic terms.

3.2   Thermal concepts 

3.2.1       Explain and distinguish between the concepts of temperature, heat                  and internal energy, in both macroscopic and microscopic terms.

3.3          Specific heat capacity, specific latent heat and ‘heat transmission’

3.3.1            Define and apply the macroscopic concepts ‘heat capacity’ and             ‘specific heat capacity’ and apply them to various problems.

3.3.2            Explain why different substances can have different specific heat          capacities.

3.3.3            Describe methods of determining specific heat capacities, and solve           related problems.

3.3.4            Describe transformations between states/phases of matter in              macroscopic and microscopic terms.

3.3.5              Explain in microscopic terms why temperature does not change when       energy is transferred into or out of a substance during a change of        state/phase, and define the specific latent heat of transformation of        a substance.

3.3.6            Solve problems involving both specific heat capacity and specific latent      heat.

3.3.7             Describe and explain conduction, convection and radiation in                 macro-and microscopic terms.  Identify and construct examples                 of each process.

3.3.8             State the factors on which the rate of ‘heat transmission’ depends in a       solid and explain the physical reasonableness of the dependencies in        the conduction equationApply the equation in steady state ‘heat        transmission’ problems.

3.3.9           Explain in terms of microscopic structure the differences between           substances with high and low thermal conductivity

3.4          Thermal properties of gases 

3.4.1          Describe simple experiments to demonstrate the relationship between     pressure, volume and temperature of a fixed mass of gas. 

3.4.2          State the macroscopic ideal gas laws relating gas pressure, volume and     temperature.

3.4.3          Discuss how ideal gas properties lead to the concept and value of the     absolute zero of temperature.

3.4.4          Solve problems using the ideal gas equation of state PV= nRT

3.4.5          Describe the microscopic (kinetic) model of a gas, and explain gas          pressure and temperature in terms of the kinetic model.

3.4.6          Use the microscopic (kinetic) model to explain qualitatively the              relationships between macroscopic pressure, volume,                   temperature and amount of a gas.  

Topic 4 – Waves

4.1 Travelling wave characteristics

4.1.1      Describe and give examples of longitudinal and transverse traveling              mechanical waves. 

4.1.2      Describe how waves transfer energy without transporting matter.

4.1.3      Define and use the terms ‘medium’ ‘displacement’ ‘amplitude’ ‘period’              ‘frequency’ ‘wavelength’ ‘wave speed’ ‘crest’ ‘trough’ ‘compression’ and              ‘rarefaction’.

4.1.4      Interpret displacement-time and displacement-position graphs.

4.1.5      Derive and apply the relationship between wavelength, frequency and              wave speed (v=fl).

4.1.6      Describe the characteristic properties of electromagnetic waves.

4.2 The behaviour of waves

4.2.1      Describe reflections in one dimension. 

4.2.2      Describe reflections of extended wavefronts in two dimensions.

4.2.3      Describe the refraction of waves in one and two dimensions. 

4.2.4      Solve wave refraction problems (including problems and examples              concerning the critical angle and total internal reflection).

4.2.5      State and apply the principle of linear superposition. 

4.2.6      Explain constructive and destructive interference.

4.2.7      Describe Young’s double slit experiment, and explain the interference              pattern. 

4.2.8      Explain the formation of beats. 

4.2.9           Describe qualitatively the diffraction of water, sound and light waves. 

4.2.10   Explain polarization qualitatively.

4.3           Standing waves  

4.3.1           Explain the formation of standing waves in one and two dimensions.

4.3.2           Describe resonance qualitatively. 

4.3.3           Solve problems involving the fundamental and harmonic resonances of      standing waves.    

Topic 5 – Electricity And Magnetism

5.1          Electric charge 

5.1.1           Show an understanding of the nature of electric charge by describing     the existence of two types of charge and the properties of conductors and insulators.

5.1.2           State and apply the conservation of electric charge.

5.1.3           Explain the concept of electrostatic induction.

5.1.4          Describe an experiment to show that the net charge on the inside of a hollow conductor is zero.

5.1.5     Apply electrostatic principles to practical situations.

5.2    Electric force, field and potential

5.2.1       State and apply Coulomb’s law.

5.2.2           Define the term ‘electric field’ and apply it to calculations for uniform electric fields.

5.2.3           Sketch electric field patterns for an isolated point charge, two like point charges, two unlike point charges, and a pair of isolated charged parallel plates.

5.2.4           Define the term ‘ potential difference’ and apply it to uniform electric field situations. 

5.3                Electric current

5.3.1             Define the term ‘electric current’ and use I=Dq/Dt

5.3.2             Describe a simple model of conduction in a metal. 

5.3.3             Define the term ‘emf’. 

5.3.4             State that potential difference in the external circuit is the power          dissipated per unit current.

5.3.5             Define resistance as R=V/I and apply this relation.

5.3.6       Describe the factors affecting resistance in conductors.

5.4     Electric circuits

5.4.1       Draw circuit diagrams using accepted circuit symbols.

5.4.2               Distinguish between ohmic and non–ohmic conduction.

5.4.3        Distinguish between conventional current and electron flow.

5.4.3               Describe the meaning of the terms ‘resistor’ and ‘internal resistance’.

5.4.5               Solve series and parallel circuits for current, p.d. and effective             resistance’.

5.4.6               Derive and apply the expressions for power dissipation in resistors.

5.4.7               Describe the use of ammeters and voltmeters.

5.4.8               Calculate and discuss the costs of using electrical energy in electrical   appliances.

5.4.9               Describe the operation of fuses and circuit-breakers in protecting               electrical circuits. 

5.5          Magnetic fields

5.5.1             Sketch the magnetic field pattern due to a straight current-carrying        conductor.

5.5.2              Sketch the magnetic field pattern due to a current-carrying solenoid.

5.5.3              Describe qualitatively the variation of field strength with position as     related to the magnetic field pattern.

5.5.4               State the dependence of magnetic field strength on current, the           number of turns, and the nature of the solenoid core.

5.5.5               Determine the direction of the force on a current-carrying conductor in    a magnetic field. 

5.5.6               Sketch the field patterns due to parallel currents, and relate these to    the directions of the forces acting on the currents.

5.5.7               State how the force between two long, parallel, current-carrying           conductors is the basis of the definition of the ampere.

5.5.8               Define the magnitude of the magnetic field strength B from F= lIB and    F = qvB for perpendicular arrangements.

5.5.9               Explain the operation of a simple d.c. motor, including the forces          exerted on its current-carrying coil. 

5.6              Electromagnetic induction

5.6.1               Describe the production of an emf induced by relative motion.

5.6.2               State and apply Lenz’s law. 

5.6.3               Draw a graph of emf as a function of time in a generator.

5.6.4               Describe the production of a transformer-induced emf.

5.6.5               Describe and solve problems on the operation of a transformer.

5.6.6               Explain the role and reasons for the use of transformers in the             transmission of electric power.

Topic 6 – Atomic and nuclear physics

6.1     Atoms and their constituents 

6.1.1             Describe the principles of Millikan’s oil drop experiment for measuring    small charges.

6.1.2       Solve problems involving a static charge of known mass suspended in               a uniform electric field of strength E.

6.1.3       Deduce from the results of Millikan’s experiment that there is a               fundamental charge.

6.1.4               Identify the fundamental charge with the concept of charge                 quantisation.

6.1.5                Describe and explain thermionic emission.

6.1.6                State the properties of cathode rays, and identify cathode rays with     electrons.

6.1.7                Describe qualititatively how Thomson was able to determine the ratio    of charge to mass of cathode rays. 

6.1.8                Evaluate the results of the Millikan and Thomson experiments.

6.1.9                Describe Rutherford’s/Geiger and Marsden’s alpha scattering                experiment.

6.1.10           Deduce Rutherford’s conclusion that the atom has a small massive        positive nucleus surrounded by electrons.

6.1.11   Evaluate the implications of Rutherford’s model of the atom.

6.2        Nuclei and their constituents

6.2.1               Demonstrate an understanding of radioactive  decay.  

6.2.2               Identify alpha and beta particles, and gamma radiation, by means of    their properties and experimental identification. 

6.2.3               Identify the products of alpha and beta decay in simple one step          transformations.

6.2.4               Describe the use of ionizing properties for detecting radiation. 

6.2.5               Identify the proton(atomic) number, Z, and nucleon (mass) number, A,   for nuclear isotopes.

6.2.6               Describe the process of artificial transmutation and solve related          problems.

6.2.7               Describe how the reaction between N and He led to the discovery of      the proton.

6.2.8               Identify the proton as the nucleus of the hydrogen atom with a            positive charge lel. 

6.2.9           Recognise that radioactive decay is a random process for individual     atoms but that the average rate of decay is exponential, and is independent of physical and chemical conditions.

6.2.10           Define the term half-life.

6.2.11          Determine the half-life of a nuclide from a decay curve.

6.2.12      Apply the concept of half-life in simple calculations involving small                integral numbers of half-lives. 

Topic 8 – Measurement

8.1   Units and mathematical techniques 

8.1.1          Apply the sine and cosine rules.

8.1.2          Manipulate the equations of exponential growth and decay, including        taking natural logarithms and exponents.

8.1.3        Apply given trigonometric identities to wave superposition problems.

8.2    Graphical techniques  

8.2.1                Using experimental or given data, choose appropriate semi-                logarithmic or logarithmic scales, plot the points with uncertainty             bars, and draw a ‘best-fit’ curve.

8.2.2                Measure and interpret the significance of the slope (gradient),                intercepts (as appropriate) under a graph with semi-log or log-log                scales, and derive any corresponding units.

8.2.3                Given a theoretical or plausible relationship between variables,           suggest transformations of powers and reciprocals to data, so as to           produce linear graphs. 

8.3       Uncertainties and errors

8.3.1          Define and calculate absolute and relative uncertainties, including        uncertainties of functions of variables with uncertainty. 

8.3.2          Propagate uncertainties through a series of calculations.

8.3.3          Qualitatively describe the issues associated with quantisation error         and sampling frequency involved in digital measurement systems.

Topic 9 – Mechanics

9.1     Dynamics

9.1.1                 Apply Newton’s laws of motion to situations involving inclined planes.

9.1.2        Demonstrate an understanding of the nature of frictional forces and                be able to solve static and dynamic problems involving friction.

9.2                  Projectile motion

9.2.1       Solve problems involving projectiles launched at an angle to the               horizontal, close to the Earth’s surface.

9.3                  Simple harmonic motion

9.3.1               Define and describe the nature of simple harmonic motion (SHM).

9.3.2               Describe and graph the relationship between displacement and time,                and velocity and time for SHM. 

9.3.3               Describe and graph, for an object executing simple harmonic motion,   the dependence of kinetic, potential and total energy on time and   displacement. 

9.3.4               Show that a mass on a light vertical spring will oscillate freely with      SHM and derive the relationship between the period, spring constant      and mass.  

9.3.5        Show that simple pendulum motion approximates to SHM for small                amplitude oscillation.

9.4                  Circular motion

9.4.1               Define the terms ‘angular displacement’ and ‘angular velocity’ and        relate them to the corresponding linear terms.

9.4.2               Relate angular displacement to linear displacement and angular           velocity to linear velocity for an object moving in a circle.

9.4.3           Show that an object moving in uniform circular motion has an           acceleration directed towards the centre, and derive an expression for its magnitude.

9.4.4           State that an object moving in uniform circular motion requires a force always directed towards the centre.

9.4.5           Describe, identify and construct examples of bodies in uniform circular motion, draw the appropriate free body diagrams, relate the motion to the forces acting and hence solve problems. 

9.4.6           Solve problems involving the motion of mass constrained to move in a vertical circle and acted on by gravity.

9.4.7      Explain why the action of the centripetal force in uniform circular              motion does not cause a change in the kinetic energy of the body. 

9.5                  Universal Gravitation

9.5.1               State and apply Newton’s law of universal gravitation.

9.5.2               Define ‘gravitational field strength’ and relate it to the acceleration      due to gravity.

9.5.3               Sketch and calculate how the gravitational field strength varies with               distance  from an isolated point mass, or sphere.

9.5.4               Define the term ‘gravitational potential’. 

9.5.5        Explain what is meant by escape velocity and calculate the magnitude                of the escape velocity for a body from the surface of a planet.

9.6                  Momentum and energy

9.6.1               Determine the work done on a body by a non constant force by            interpreting a force-displacement graph.

9.6.2               Describe the behaviour of a linear spring under a displacing force, and   determine the spring constant.

9.6.3               Describe the concept of elastic potential energy and apply this to         solve problems.

9.6.4               Deduce the law of conservation of momentum for a closed system of    two bodies, from Newton’s laws.

9.6.5        Apply the principle of conservation of momentum in two dimensions                to solve problems.

9.7                  Rotational Motion Of A Rigid Body

9.7.1               Define the terms ‘angular acceleration’, ‘torque’, ‘the moment of               inertia’ and ‘angular momentum’.

9.7.2       Relate the equations of linear dynamics to those of rotational               dynamics and solve problems by applying the relevant equations.