Extended Investigation – selecting a topic

The paper linked below provides some suggestions for Extended Investigation topics.  It also has a limited list of pass topic titles.  The topics are (roughly) grouped by discipline.  It contains a few hints about conducting an Extended Investigation.

The paper has two appendices, "A List of Some Successful Extended Investigation Topics" and "Some Statistics on School Participation".

ex_invest_topics.pdf  08/12/2025
    Physics 1/2 and 3/4 Practical Investigations – some ideas

Disclaimer: This site does not address the VCAA safety requirements.

The ideas presented below do not carry any authority.  They could, however, provide a starting point for development by student and teacher.  The ideas are organized by unit, but this structure is loose because the concepts will transfer readily from one unit to another, for example by adding or removing an independent variable.  Each idea is introduced on this page with a brief description and access to a more comprehensive description in PDF format.

The VCAA is obsessed with the requirement that the title of the investigation must be in the form of a question.  Thus "A succinct proof of the 4 colour theorem" would not serve as a title, I guess it would have to be "Is this a succinct proof of the 4 colour theorem?". 

It is argued by some, only slightly cynically, that an academic paper (or poster) should be written back to front and inside out.  After the experimental work decide on what you have found and write the conclusion, now write the introduction to match the conclusion, organize your investigations to systematically substantiate your conclusion, and finally settle on a title.

Ideas for Systems Engineering investigations can be accessed via the Systems Engineering tab in the header bar.

    Physics 1/2
GPS repeatability:– satellites, EM wave propagation, instrumentation

Repeatability is a desirable parameter in scientific instruments – how closely will a future reading in like circumstance match the current reading? 

This idea has a minimal requirement for additional equipment.

gps_repeatability.pdf

Low Pass Filter:– capacitors, electronics, instrumentation, logarithmic scales and units.

A low pass filter can be constructed with two components, a resistor and a capacitor.  The combination of a lossy component with a storage component occurs in many situations other than electronics.

low_pass_filter.pdf

Virtual Extension:– Hooke's Law, extension springs, preloading, extracting parameters from experimental data.

The 'standard' extension spring is preloaded.  This means that the "free" length does not equal the "unloaded" length.  Here we look at a means of determining the "virtual" free length.

virtual_free_length.pdf
    Physics 3/4
Galileo's Density Determination Device:– Galileo, relative density, beam balance formula, Archimedes' principle

In 1586 at the age of 22, Galileo (1564-1642) wrote a short treatise entitled La Bilancetta (“The Little Balance”).  His method enabled the density of precious metals to be determined by the measurement of the ratio of two lengths.  This project investigates his method, there is ample scope to meet the VCAA requirements.

galileo_density.pdf

Lenz’s Law and Terminal Velocity:– Lenz’s Law, terminal velocity, velocity dependent forces, free body diagrams

A bar magnet free falling down the inside of a conducting tube will reach terminal velocity when the weight force equals the opposing magnetic force as formulated by Lenz’s’ law.  This condition occurs because the opposing magnet force increases with velocity

magnetic_terminal.pdf

Measuring Speed by Magnetic Induction:– Lenz's Law, rate change of flux, sensing coils

To do this experiment the student would need access to a digital storage oscilloscope, (DSO).  In other respects this project is straightforward and meritorious.

speed_measurement.pdf

Calibration Check on a Microwave Oven:– calorimetry, power and energy, concepts, thermal capacity

Basic microwave ovens are calibrated in watts delivered to the item being heated.  How accurate are these calibrations?  Do they depend on the nature of the load?  Only kitchen level equipment required.

microwave_oven.pdf

Pressure - Flow Characteristics of small bore nozzle:– pressure, flow, head – pressure relationship

A data analysis project relating flow of water through a nozzle to pressure.  Generally only readily obtainable equipment required for this project.

pressure-flow.pdf

Characteristics of Tennis Balls:– characteristics, specifications, consistency

The opportunity exists for a student to do something more meaningful than just a bouncing ball.

tennis_balls.pdf

Distortion in Camera Lens:– camera, distortion, pincushion, barrel

Lens design for pocket sized digital cameras is a situation of optimization and compromise.  Lenses have to be compact, light, economic and cover a wide range of focal distances and have good zoom capabilities.  Very little equipment is required for this project.

lens_distortion.pdf

Inside-out AC Generator:– armature, magnetic field, AC output

There are advantages in building a simple inside-out AC generator if required for class room demonstrations.  An inside-out a generator has a stationary armature and a rotating magnetic field.

insideout_generator.pdf

Torsion Springs:– torsion springs, spring constant, torque angular deflection

Numerous experiments have been done on the spring constant for linear springs.  This investigation considers the spring constant of torsion springs.  It requires the construction of a simple piece of additional equipment.  The student would not (in my understanding) be required to do the construction work.

torsion_springs.pdf

Two Linked Masses and a Pulley:– Newton's Second Law under control.

Can the acceleration of a falling body be scaled uniformly and predictably with a simple mechanical configuration?  For example, an additional force, a parachute say, may modify the acceleration.  However such techniques are difficult to quantify, this investigation takes a different approach.

two_linked_masses.pdf

Compound Springs:– kinking Hooke's Law, springs in series

Standard linear springs may be arranged to give a non-linear force/displacement relationship.  With a minimum of equipment and setting-up there is ample scope for acquiring data while investigating this process.  Formulae may be derived to provide a comparison between theory and acquired data.

compound_spring.pdf

Balancing a Beam:– levers, moments, centre of mass

The balance of a uniform beam pivoted off centre can be corrected with the addition of a suitable mass placed at a suitable position.  With a minimum of equipment and setting-up there is ample scope for acquiring data while investigating this process.

beam_balance.pdf

Angular Inertia:– angular variables as analogues of linear variables and bicycle wheels

There are formulae for calculating the angular inertia of standard shapes. a plain uniform disc for example.  However for more complex shapes composed of differing material the calculations are difficult and a practical approach may be preferred.

angular_inertia.pdf

Length of Glockenspiel Bars:– acoustics, frequency, linearization

Eight bar glockenspiels (a glockenspiel, has metal bars, a xylophone has wooden bars) are readily available.  There is a relationship between the frequency of each note and the length of the bar that can be investigated.

investigations/glockenspiel.pdf

Non-linear spring configurations:– Hooke's law, vector addition, variable spring stiffness

Linear springs can be used in non-linear configurations.  In this project the researcher investigates and analyses a non-linear spring arrangement.

investigations/non-linear_geometry.pdf

Notch Filter:– capacitors, electronics, instrumentation, logarithmic scales and units,

A notch filter can be constructed with several resistors and capacitors.  These filters have been thoroughly analyzed – how well does theory match practice?

notch_filter.pdf

Electric Jug Efficiency:– calorimetric, temperature measurement, heat flow and storage.

The electric jug is probably the most efficient electrical device in a household.  An electric jug uses electrical energy to heat water.  Because of the intimate contact between the heating element and the water almost all the electrical energy is transferred to the water.  So what is the efficiency?

electric_jug_efficiency.pdf
    Other Ideas, Mathematics, Software
Other Ideas, Mathematics, Software
Weather Prediction:– data management, algorithms and touching the edge of AI

Can we predict tomorrow's temperature without looking at the barometer or the clouds?  This investigation is novel in that it does not use laboratory data but data from an external source.

weather-data.pdf

Champernowne Constant:– The peculiarities of the Champernowne Constant

The Champernowne Constant is a remarkable constant, its value depends on the number base used to determine it.  This peculiar characteristic means that there is great scope for investigation.

champernowne.pdf

Monty Hall Problem:– a paradox in probability

When this pick-the-valuable-door game-show exposed an apparent probability paradox there was intensive debate between well qualified people.  Recent analysis has resolved the issue, but there is always scope for further software and/or mathematical work.

monty_hall.pdf

Lawn Bowls:– it's more complicated than you think

Bowling tournaments are held on a green.  The green is divided into rinks, a game is played between teams on a rink.  A tournament consists of a number of rounds.  Ideally the scheduling of games is done with perfect symmetry (in the broad physics sense) so as not to disadvantage/advantage any team.

lawn_bowls.pdf

Silver Triangle:– a competitor for the gold rectangle?

An approximation to a spiral can be constructed on a sequence of Golden Ratio rectangles.  It has some mathematical considerations and is popular with the arts community who make absurd claims about its values.  A similar construction can be made with a sequence of triangles.  Although not as accessible to the viewer as the rectangle sequence, there is material for investigation.

silver triangle.pdf

Triples:– this suggestion has not been developed

Pythagorean Triples (a good introduction is available at Maths is Fun) have become dog-eared with constant working over.  The PDF file may suggest some fresh geometric areas for investigation.

triples.pdf