Domain: Natural Science — Physics
Target concept: Hooke's Law

Video generation prompt: Two identical spring scales are vertically suspended in parallel with one end fixed to the wall. A metal weight of 500 g is hung from the left spring scale, and a metal weight of 1000 g is hung from the right spring scale.

Evaluation guide:
(i) Target concept: Linear elastic response of identical springs under proportional loads.
Minimum mechanism: Springs must behave as ideal linear elastic elements (no yielding, no hysteresis, no creep); gravitational acceleration uniform; weights fully at rest (static equilibrium); no external forces (e.g., air currents, vibration) perturbing system.
(ii)Storyline: Frame 1–2: Two identical spring scales mounted side-by-side on wall, both unextended. Frame 3–4: 500 g weight attached to left scale hook; right scale remains unweighted. Frame 5–6: 1000 g weight attached to right scale hook. Frame 7–10: Both weights hang steadily; left scale shows moderate downward extension; right scale shows greater downward extension; all objects remain fixed in place with no motion, oscillation, or detachment; viewpoint is frontal, static, and centered on both scales and weights.

Manual:
Experimental Procedure
1. Mount two identical spring scales vertically and parallel on the same wall surface.
2. Hang a 500 g metal weight from the hook of the left spring scale.
3. Hang a 1000 g metal weight from the hook of the right spring scale.
Observation of Experimental Phenomena
The right spring scale extends farther downward than the left spring scale; both scales remain stationary in static equilibrium after hanging.
Summary of Experimental Principles
Hooke’s Law states that the extension of an ideal spring is directly proportional to the applied force (F = kx); since weight = mg, the 1000 g mass exerts twice the force of the 500 g mass, resulting in approximately twice the extension.

Prompt Grounding rubric:
level_1: No two spring scales are shown; no metal weights are present; no wall-mounted fixed point is visible; the scene shows no resemblance to two parallel wall-mounted spring scales with hanging weights.
level_2: Only one spring scale is visible instead of two, or the two scales are not mounted side-by-side on the same wall, or a weight is missing from one or both hooks; at least two of the core objects (two scales, wall, two weights) or their side-by-side parallel arrangement described in the prompt are missing.
level_3: Two spring scales hang vertically side-by-side from the same wall, each with one weight attached to its hook; however, the two weights look identical in size with no numeric marking or tag, so a viewer cannot tell which one is meant to be the 500 g weight and which is the 1000 g weight from the objects alone.
level_4: Everything in score 3 holds, and the two weights are visually distinguishable from each other by physical size (a visibly larger block or plate for the 1000 g weight) or by an attached numeric label/tag showing their mass, independent of how far each spring has stretched; no scale or weight is duplicated, teleported, or misplaced relative to the wall or its hook.
level_5: Everything in score 4 holds, and each weight hangs only from its own scale's hook with no crossed cables, shared attachment point, or unattached floating weight; both scales keep the same vertical, parallel orientation to each other for the whole clip; the wall mounting shows no bending, detachment, or instability, matching the posted prompt's static two-scale setup exactly.

Scientific and Causal Correctness rubric:
level_1: Neither spring visibly stretches once its weight is attached; or both springs stretch by the same amount despite carrying different masses; or the spring under the 1000 g weight ends up shorter or less stretched than the spring under the 500 g weight, contradicting Hooke's Law.
level_2: Only one of the two springs shows any visible stretching while the other stays at its unloaded length; or a spring appears to shorten or compress instead of extend once weighted; or at some point after both weights are attached the 500 g spring looks more stretched than the 1000 g spring.
level_3: Both springs extend downward from their unloaded length once their weights are attached, and the spring holding the 1000 g weight ends up more stretched than the spring holding the 500 g weight, showing that the heavier load produces the greater extension; however the video does not clearly show both springs settling into a steady final length: for example one is still visibly bouncing or drifting when the clip ends.
level_4: Everything in score 3 holds, and both springs reach a visible resting length with no further oscillation or bouncing, holding that steady length for at least the last three-quarters of the clip; the 1000 g spring's resting extension stays clearly and continuously greater than the 500 g spring's, consistent with the load being proportional to the applied weight.
level_5: Everything in score 4 holds, and the size of the extension difference looks proportionate to the mass difference: the 1000 g spring's added stretch beyond its unloaded length appears roughly twice that of the 500 g spring's, with no moment showing equal extension or a reversal, and no non-Hooke's-Law behavior such as one coil bunching up or buckling while the other stretches smoothly.

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal rupture: one or both spring scales vanish or appear mid-video; a weight jumps from its hook to a different position without any in-between motion; the wall panel behind the scales changes shape, color, or position abruptly; the room's lighting or the scales' shadows abruptly flip or reverse direction with no cause; a scale that was intact suddenly shows a broken or missing hook and then appears whole again.
level_2: Moderate rupture: one scale visibly slides sideways or rotates more than about 15 degrees without any smooth in-between motion; a weight briefly detaches from its hook and then reattaches on its own; a visible jump-cut changes a weight's position between consecutive frames with no settling motion shown; the wall behind one scale looks like a different material, color, or angle than moments before.
level_3: Both scales stay fixed to the same wall region and keep their side-by-side arrangement throughout, but a viewer watching normally would still catch a small glitch: for example the pointer or hook on one scale flickers or briefly changes shape, or a weight visibly swings side to side once instead of hanging still, before everything settles back into place.
level_4: Both spring scales stay parallel and vertical, equally spaced from each other and from the wall edge, for the entire clip; each weight hangs directly beneath its own hook with no visible sideways drift; the coils of each spring keep a consistent, smoothly graded spacing from top to bottom with no kinks or gaps appearing and disappearing; any settling motion after the weights are attached looks like gentle physical damping rather than a sudden jump.
level_5: Everything in score 4 holds, and both scales, their hooks, and both weights hold their exact relative positions and proportions in every frame with no flicker, warp, or double-image of any part; the coil spacing and pointer position on each scale change smoothly and only in the downward-stretching direction once weights are attached, never snapping backward or sideways; the camera framing of both scales and the wall behind them stays completely fixed with no pan, tilt, or zoom.