Choosing and researching a context
The grade is largely decided before you write
Most of the difference between a Merit and an Excellence report is decided before any writing happens — in the choice of context and in how the research is done.
What makes a good context
- It contains several genuine Level 7 physics concepts, not just one.
- A context with only one applicable concept makes Excellence almost impossible, because Excellence requires linking ideas together.
- The physics is central to how the thing works, not incidental.
- You can find or take realistic numbers for it — masses, speeds, power ratings, temperatures, wavelengths.
- It is specific. "Sport" is not a context; "why a cricket bat has a sweet spot" is.
Contexts that work well, and the physics in each
| Context | Physics you can bring in |
|---|---|
| Car safety (crumple zones, seatbelts, airbags) | momentum, impulse, work and energy, forces |
| A hydro scheme (e.g. Manapōuri or Clyde Dam) | gravitational potential energy, kinetic energy, , efficiency, electromagnetic induction |
| Solar hot water on a NZ house | heat transfer, specific heat capacity, energy efficiency, radiation |
| Ultrasound scanning | wave speed, reflection, frequency and wavelength, |
| A guitar or a taonga pūoro | standing waves, harmonics, resonance, frequency and pitch |
| Cycling and helmets | impulse, momentum, energy transformation, friction |
| Rescue helicopter winching | forces, Newton's laws, tension, work and power |
| Electric vehicles | electrical power , energy storage, efficiency, regenerative braking |
Researching without copying
- The clarification for this standard is explicit: paraphrasing and summarising alone do not show understanding. You must show that you have processed the information.
- Signs that you have processed it:
- You applied the idea to a specific feature of your context, with your own reasoning.
- You did a calculation with numbers from your context.
- You drew your own diagram rather than reproducing one.
- You explained why something is designed a particular way, not just what it is.
- Reference your sources. It is good practice, it supports authenticity, and it lets your teacher see that a striking claim came from somewhere real. Referencing does not by itself earn marks.
Using your own measurements
- Where the context allows, take your own readings — the power rating on an appliance, the time for a ball to fall, the length and frequency of a guitar string.
- Own data is strong evidence because it cannot be copied, and it gives you realistic numbers for a calculation, which is one of the easiest routes into Merit.
Planning the report before you write it
- List the features of the context you could explain (three or four).
- Against each, write the physics concept that explains it.
- Cross out any feature where you cannot name a concept — that is description, not physics.
- For each surviving feature, note whether you can add a calculation.
- Look for links between the concepts you have listed — those links are your Excellence material.
Worked ExampleAuditing three possible contexts
A student is choosing between three contexts for their AS91169 report: (a) the physics of rugby, (b) a hydroelectric dam on the Waikato River, and (c) an electric jug. Audit each and choose one.
Step 1 — Audit context (a): the physics of rugby
| Feature | Physics concept | Calculation possible? |
|---|---|---|
| A player being tackled | impulse and momentum | yes — |
| Kicking for goal | projectile motion | yes — range and angle |
| A scrum not moving | balanced forces / equilibrium | yes |
| Scrum caps and padding | impulse, extending contact time | yes |
Verdict: four features, four concepts, calculations throughout — but the context is broad, so there is a real risk of writing four shallow paragraphs. Workable if narrowed to, say, the tackle alone.
Step 2 — Audit context (b): a hydroelectric dam
| Feature | Physics concept | Calculation possible? |
|---|---|---|
| Water held behind the dam | gravitational potential energy, | yes |
| Water falling to the turbine | conversion of to | yes |
| Turbine driving a generator | electromagnetic induction | yes |
| Power output of the station | and efficiency | yes |
| Transmission to cities | and losses | yes |
Verdict: five features, five concepts, and — critically — they link into a single chain: potential energy becomes kinetic, which becomes electrical, which is then transmitted with losses. Strong Excellence potential, and it is a genuinely New Zealand context with real published figures available.
Step 3 — Audit context (c): an electric jug
| Feature | Physics concept | Calculation possible? |
|---|---|---|
| Element heating the water | electrical power, | yes |
| Time to boil | energy transfer, | yes |
| Heat lost to the room | efficiency | yes |
Verdict: three features, but they are all the same idea — electrical energy becoming heat — expressed three ways. There is little to connect because there is only one concept underneath. Likely to cap at Merit.
Step 4 — Choose, with a reason
It has the most concepts, they are genuinely different from one another, every one supports a calculation, and — the deciding factor — they form a causal chain in which each stage explains the next. That chain is exactly the "connections between concepts" that Excellence requires.
Context (a) could also work if narrowed to a single feature such as the tackle. Context (c) should be avoided: it looks approachable, but it cannot supply the connections.