Public teacher-targeted… | Year 11 Physics · T1 W1–2 · Key And Next

This file is publicly accessible by URL. Check A/B are fresh relative to practice but not secure exams, QCAA instruments or a certified unit result. Separate physics explanation, calculation/unit and assumption, and claim boundary in feedback; also log source access, response mode, calculator, time and any content hint. Use “clear in this response / partial or hinted / not yet evidenced” only as a next-teaching note, not a QCAA achievement judgment. All figures and objects are invented. No real experiment or safety claim is supported.

Daily worked models and next actions

Day	Source-bound answer	Next move when evidence is thin
01	Same material and phase at 60 °C supports the same model average particle kinetic-energy state, not equal total internal energy. A 1.00 kg sample contains five times the mass of a 0.20 kg sample; the equal-size drawing is not to scale. Do not state a joule value or an exact energy ratio without more assumptions/reference data.	Ask “per particle average or whole sample?”; place MASS beside each bowl.
02	The continuous solid bridge connects higher and lower model temperatures, so conduction is a possible energy path without bulk metal movement. There is no transfer-rate or safe-touch evidence.	Trace a path through named material; ask what the sketch did not measure.
03	In the stipulated diagram, air moves in the proposed loop and energy is transferred by convection. The 23 °C lower and 27 °C upper labels do not by themselves measure flow direction or speed; “warmth rises as a substance” is misleading.	Make separate AIR MOTION and ENERGY TRANSFER arrows; mark the proposed arrow as modelled.
04	Thermal radiation can cross the evacuated gap. Conduction and convection cannot act through that empty gap because there is no matter there; a solid support elsewhere could conduct if supplied. The received fraction/rate is unknown.	Keep the qualifier “through the gap”; ask for a receiver/property measurement before power claims.
05	The constructed crate can include conduction through the wall, convection within moving air, and radiation between facing surfaces. A diagram supplies no food temperature, time or food-safety proof.	Assign a different named location to each mechanism and remove proven safe.
06	QCAA rounded convention: `22+273=295 K`; `−5+273=268 K`. Final minus initial is −27 K; equivalently a 27 K decrease. A temperature interval is not given another +273. The exact SI offset is 273.15, beyond this stated syllabus convention.	Convert each temperature first, then subtract; remove degree sign from K and keep the decrease direction.
07	`27.0−18.0=9.0 °C`. With stipulated ±0.1 °C for each reading, a conservative worst-case difference bound is ±0.2 °C, so `ΔT=(9.0±0.2) °C`. Percentage bound `0.2/9.0×100≈2.2%`. Decimal display alone does not establish calibration accuracy or eliminate common bias.	Ask where the ±0.1 came from (the note, not the last digit); put uncertainty next to the difference before dividing.
08	`Q=mcΔT`: `0.50 kg×2,000 J kg⁻¹ K⁻¹×4 K=4,000 J`; `1.00 kg×2,000×4=8,000 J`. In the stipulated single-phase/no-loss model, doubling mass doubles Q at fixed c and ΔT. No heater rating or actual loss is known.	Cancel kg and K; hold c/ΔT constant on both rows.
09	`ΔT=Q/(mc)`. Aster: `3,000 J/(0.50 kg×1,000 J kg⁻¹ K⁻¹)=6 K`; Beryl: `3,000/(0.50×2,000)=3 K`. Same energy and mass, different stipulated c; no real tile safety follows.	Check which variable changed, then point to c in the denominator.
10	From `(1 K,1,000 J)` and `(3 K,3,000 J)`, `slope=ΔQ/ΔT=2,000 J/2 K=1,000 J K⁻¹`. Since `slope=mc`, `c=1,000 J K⁻¹/0.25 kg=4,000 J kg⁻¹ K⁻¹`. The four points are calculated in a no-loss, constant-c, single-phase range; they cannot prove a universal or experimental relationship.	Distinguish line slope from c by dividing by mass; ask whether any points were measured (no).

Check A worked response · light-box route map

The fictional designer addresses gallery visitors. All and never enlarge a diagram into an untested performance/safety promise. The evacuated gap has no air: thermal radiation can travel from emitting panel toward receiver through it, but air convection cannot operate through that gap. Conduction can occur along the touching solid bracket; convection can occur in moving air of the outer air-filled housing if its proposed flow occurs. The arrow is a model, not an observation. A suitable correction is: “The invented diagram permits a radiation path across the evacuated gap, a solid-bracket conduction path and a proposed outer-air convection path. It provides no temperature, heat-rate or safety measurement.”

Next moves: If the learner puts convection in the gap, ask them to locate matter there. If they say no conduction anywhere, point to the touching bracket. If they present safe as a result, ask for temperature, time, receiving-surface and operating-condition data; do not improvise a real test.

Check B worked response · gallery-board model line

Using (2 K,800 J) and (6 K,2,400 J), slope ΔQ/ΔT=(2,400−800) J/(6−2) K=1,600 J/4 K=**400 J K⁻¹**. In Q=mcΔT, slope is mc, not c. Divide by sample mass: c=400 J K⁻¹/0.40 kg=**1,000 J kg⁻¹ K⁻¹**. The public caption omits the 0.40 kg mass and generalises beyond the four calculated points. A bounded replacement is: “For this fictional 0.40 kg single-phase no-loss model over 0–6 K change, Q rises by 400 J per kelvin, corresponding to model c = 1,000 J kg⁻¹ K⁻¹. No real-material or wider-range result was measured.”

Next moves: If 400 is reported as specific heat capacity, ask what mass has to be divided out. If the unit is J/K for c, use the Q=mcΔT unit cancellation. If the learner calls the points experimental, return to the source's calculated model label and missing uncertainty bars.