2026 SACE Physics exam: What to learn from last year's mistakes

Exam: Thursday 5 November 2026, 9.00 am. South Australia local time.

I've gone through last year's examiner advice. Several difficult questions weren't about finding another equation. They were about explaining why the physics applied. The report doesn't publish an overall exam mean or question averages, so I haven't invented them.

1. Q7: Use the conservation law the question asks for

Where students went wrong

Many answers used Newton's Third Law or energy conservation instead of momentum conservation.

What they should have done

For the ion thruster, explain how the backward momentum change of the xenon ions is balanced by the forward momentum change of the thruster. Connect changing momentum to force and acceleration.

As a practice check, write the system you are considering before writing the law. If external forces can be neglected, the total momentum of that system remains constant. Then describe what changes inside it. “Action and reaction” alone doesn't answer a momentum question.

2. Q11: Write an experiment someone could actually run

Where students went wrong

Methods were sometimes impractical or failed to explain how measurements would be taken.

What they should have done

Name the independent and dependent variables, explain how to change and measure them, and specify how controls stay constant. The examiner advice called for at least five data points and three measurements per point to calculate an average.

Test your method by handing it to an imaginary classmate: could they produce your intended table without asking you what to do next? “Repeat for accuracy” doesn't tell them what to repeat or record.

3. Q15(b): More intense light doesn't mean more energetic photons

Where students went wrong

Responses often restated the question or relied on a formula without explaining the energy transfer.

What they should have done

Explain the one-photon-to-one-electron interaction. Photon energy depends on frequency. Increasing intensity at fixed frequency doesn't increase each photon's energy, so it doesn't increase the maximum photoelectron kinetic energy.

Use Kmax = hf − φ as a check: at fixed f and fixed metal, both terms on the right stay unchanged. Say what stays constant and connect it to the requested outcome.

4. Q21(b): Lenz's law needs the changing flux

Where students went wrong

Some answers named Lenz's law without linking the weakening field to changing magnetic flux through the pan.

What they should have done

Identify the flux change first, then explain how the induced field opposes that change. Finally connect that field direction to the eddy-current direction.

A useful writing sequence is: what changes → what induced field opposes that change → which current direction produces that field. Check the viewing direction before calling a current clockwise or anticlockwise.

These are selected lessons, not a prediction of this year's questions. Read the 2025 examiner advice with the official examination materials and check the 2026 timetable.

Sorry guys, shameless plug, I gotta do this. I'm the founder of ATARMAXXING, so take a look at the SACE Physics practice exams with worked answers if you want more practice. You can preview the Physics pack before buying. Try an explanation question and check whether every link in your reasoning is actually on the page.

Discuss this SACE Physics exam breakdown on the subject board.