§ Year 9 · Physics strand of Science · Australian Curriculum
Year 9 Physics.
The year energy stops being qualitative.
Year 9 students sit Science as one subject in Queensland, not separate Physics. This page is about the physics strand inside Year 9 Science — conservation of energy, energy transfer, Sankey diagrams, and the particle model behind electricity. If that strand is where your child is struggling (or where they want to push ahead before senior Physics), Pythora can focus there.
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§ What Year 9 covers
The syllabus, in plain English.
Year 9 Science follows the Australian Curriculum v9. The physics-strand content for Year 9 takes the energy ideas from Year 8 and pushes them harder — the law of conservation of energy is taught explicitly (it was Year 10 under the old syllabus and has moved down), Sankey diagrams come in as a tool for tracking useful vs wasted energy, and energy efficiency calculations appear. The electricity content moves into the particle-model view of charge, with static electricity, current as flow of charge, and qualitative work on voltage. Year 9 also revisits how the model of light and sound waves works as another form of energy transfer.
Physical sciences strand — Conservation, transfer and electricity (Year 9 Science)
- Law of conservation of energy — total energy is constant in a closed system
- Sankey diagrams — drawing and interpreting energy flow
- Energy efficiency — calculating useful output ÷ total input as a percentage
- Particle model and electric charge — static, conductors and insulators
- Current as the flow of charge and qualitative voltage
- Waves as energy transfer — light, sound, longitudinal vs transverse
§ Where Year 9s get stuck
Common pitfalls — and how to dodge them.
Drawing Sankey diagrams without scaling the arrows
A Sankey diagram is meant to show energy proportions visually — the width of each arrow has to match how much energy is in that branch. Year 9 students often draw all the arrows the same width and lose marks for it. We teach the technique with grid paper from the first session: total input across, then split the widths proportionally.
Calculating efficiency the wrong way around
Efficiency = useful energy output ÷ total energy input × 100%. Year 9 students sometimes flip the fraction or use the wasted energy instead of the useful. An efficiency over 100% is the giveaway that the fraction is upside down — but in an exam under time pressure, plenty of students still hand it in. We drill the formula until the direction is automatic.
Treating "conservation of energy" as a slogan instead of a tool
Conservation of energy is more than a quote — it lets you solve problems. If a 100 J input produces 30 J of useful output, the missing 70 J has gone somewhere as heat, sound, or another transfer. Year 9 students who can quote the law often can't apply it. We use it as a working tool every session.
Confusing charge and current
Charge is a property of particles (electrons have negative charge). Current is the flow of charge per unit of time. Year 9 students mix them up constantly, which causes endless trouble in Year 11 Physics. We separate them on day one and don't let them be used interchangeably.
Calling all waves the same kind
Sound waves are longitudinal (the particles vibrate in the same direction as the wave travels). Light waves are transverse (particles or fields vibrate at right angles). Plenty of Year 9 students write generic "wave" answers that ignore the difference. The difference is graded.
§ Worked examples
A question. A walkthrough. The marks.
Example 1
Calculating energy efficiency
The question
An electric kettle is supplied with 2000 J of electrical energy. It transfers 1700 J as useful heat to the water and 300 J to the surroundings as wasted heat. What is the efficiency of the kettle?
Walkthrough
Step 1 — Identify the useful output. Useful = 1700 J (the heat that actually warms the water). Step 2 — Identify the total input. Total = 2000 J (the electrical energy supplied). Step 3 — Write the formula. Efficiency = (useful ÷ total) × 100%. Step 4 — Substitute and calculate. Efficiency = (1700 ÷ 2000) × 100% = 0.85 × 100% = 85%. Step 5 — Sanity-check using conservation of energy. The 300 J of wasted heat plus the 1700 J of useful heat add to 2000 J, which matches the input. Energy is conserved, the answer is consistent. Mark allocation: 1 for the formula, 1 for the substitution, 1 for the calculation, 1 for the percentage sign and the conservation check. Students who write "0.85" with no percentage sign lose a mark routinely.
Example 2
Static charge — explaining a balloon sticking to a wall
The question
A student rubs a balloon against their hair and the balloon then sticks to a wall. Using the particle model and the idea of electric charge, explain why this happens.
Walkthrough
Step 1 — Identify what happens during rubbing. When the balloon is rubbed against hair, electrons are transferred from the hair to the balloon. The balloon ends up with extra negative charge; the hair is left positively charged. Step 2 — Explain what happens when the balloon is held to the wall. The negative charges on the balloon repel electrons in the wall surface, leaving the wall surface positively charged in that small region. Step 3 — Identify the force. Opposite charges attract. The negative balloon and the now-positive wall surface attract each other, holding the balloon in place. Step 4 — State the conservation point. No charge is created or destroyed — it is just transferred from the hair to the balloon, and the wall is polarised, not charged overall. A Year 9 question typically gives 4 marks: 1 for identifying electron transfer, 1 for naming the charges correctly, 1 for explaining the attraction, 1 for the conservation statement. The conservation sentence is the one most students forget.
§ Why Pythora for Year 9 Physics
Not generic tutoring. Specifically this.
Tutors who scored highly in senior Physics, working back to Year 9
Every Pythora physics tutor sat senior Physics within the last few years. They know which Year 9 ideas the Year 11 Physics syllabus assumes you already understand cold, and they teach Year 9 with that in mind.
Sankey diagrams and efficiency questions drilled properly
These are the calculation questions Year 9 students lose the most marks on. We work through past papers and exemplars until both the diagram technique and the formula direction become automatic.
Senior-Physics-ready by the start of Year 11
For students who already know they want to do Year 11 Physics, the gap between Year 10 Science and Year 11 Physics is the steepest in the QCAA syllabus. Strong Year 9 physics — especially the energy and electricity content — is the cheapest place to start closing that gap.
A written recap of every session, automatically
You see exactly what was covered, where your child struggled, what was set as homework, and what next week will focus on. In your inbox inside six minutes of the lesson ending.
§ Real student
“I always thought I'd hate Physics in Year 11. After tutoring this year I'm actually considering it. The energy stuff finally makes sense.”
§ Where this fits
One step on the path.
Year 9 conservation of energy and electricity content sits underneath Year 10 motion, and underneath all of Year 11 Physics. If energy efficiency and the charge-vs-current distinction are not solid here, Year 11 Unit 1 (electricity and circuits) feels much harder than it should. Year 9 is the cheapest year to build the foundation.
Builds from
Year 8 Physics (energy strand)Leads to
Year 10 Physics (motion strand)§ Questions
Frequently asked.
Why does the page mention senior Physics if my Year 9 doesn't take it yet?
Year 10 is when students choose their senior subjects, including whether to take Year 11 Physics. The students who handle Year 11 Physics well are almost always the ones whose Year 9 and Year 10 physics-strand content was solid. We tutor Year 9 with that runway in mind — not because your child has decided yet, but so the option is genuinely open.
My child is in Year 9 and the school covers energy in one term. Is short-term tutoring useful?
Yes. Four to six sessions during the energy unit can lift a struggling student from confused to confident, and they leave with the Sankey-diagram and efficiency-calculation habits that show up again in Year 10 and Year 11.
Will the tutor cover the maths needed for efficiency calculations?
Yes — efficiency is a percentage calculation, and Year 9 students sometimes need a refresher on percentages and fraction manipulation. If the gap is more about maths than physics, the tutor will say so and you can switch to maths tutoring (or do both).
How much does Year 9 Physics tutoring cost?
Year 9 Physics (the physics strand of Year 9 Science) is $75 per hour as a Junior subject. Billed weekly for completed sessions, no lock-in. Every new family gets a free trial session with their matched tutor first.
Year 9 Physics.
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