Domain: Natural Science — Physics
Target concept: Strike the tuning fork with a small hammer, and touch the prong of the tuning fork to the water surface. Verify that dense small splashes immediately appear on the water surface and continue as the vibration persists.

Video generation prompt: A hand holds a metal tuning fork and a small hammer. The small hammer strikes the tuning fork once. The vibrating tuning fork is then immediately moved so that its prongs gently touch the still surface of the water in a shallow container. The entire process is clearly and continuously presented, with emphasis on the tuning fork, the water surface, and the hand movements.

Evaluation guide:
(i) Target concept: Mechanical vibration transmission from solid to liquid medium induces observable surface disturbance.
Minimum mechanism: Tuning fork must be rigid and elastic enough to sustain free vibration after impact; water must be at rest and shallow enough to allow direct prong immersion without damping vibration prematurely; contact must be gentle to avoid large-scale displacement (splashing) and isolate vibration-driven micro-splashes.
(ii)Storyline: Frame 1–2: Hand holds tuning fork + hammer in static readiness. Frame 3–4: Hammer strikes fork, visible recoil/motion of fork body. Frame 5–6: Fork begins oscillating (prongs visibly diverging/converging). Frame 7–8: Hand moves fork toward water; prongs approach surface. Frame 9–10: Prongs make first contact → immediate appearance of ≥3 small splashes. Frames 11–end: Splashes persist densely and uniformly *only while* prongs vibrate *and* remain in contact; cease instantly upon lift-off. Perspective: Fixed frontal/slightly angled view showing hand, fork, hammer, container rim, and full water surface; no occlusion of contact zone; water surface must dominate lower third of frame.

Manual:
Experimental Procedure
1. Hand holds a metal tuning fork and a small hammer.
2. Hammer strikes tuning fork once.
3. Vibrating tuning fork is moved so prongs gently touch still water surface in shallow container.
Observation of Experimental Phenomena
Dense small splashes appear immediately on water surface upon contact and persist continuously while prongs vibrate and remain in contact.
Summary of Experimental Principles
Striking the tuning fork sets it into mechanical vibration; touching the vibrating prongs to water transfers kinetic energy, causing rapid localized displacement of water molecules — observed as dense, small, persistent splashes.

Prompt Grounding rubric:
level_1: Score 1 applies if any single one of the following is missing from the clip: no tuning fork visible, no hammer visible, no hand visible, no shallow water container visible, or no moment where the fork's prongs touch the water surface.
level_2: Only one or two of the core elements show up (say, a hand and a fork but no hammer, or a fork with no water container in sight), and there is no strike-then-move-then-touch sequence: for instance the fork is just shown resting in or near the water with no prior strike.
level_3: A hand, a metal tuning fork, a small hammer, and a shallow water container are all visible, and the clip shows the hammer striking the fork followed by the fork being carried to the water; but one part is weak, such as the strike itself being hard to see, the fork only grazing the water for an instant rather than settling into contact, or part of the hand's path to the water being hidden.
level_4: All five elements (hand, tuning fork, hammer, container, and water surface) stay clearly visible for the whole clip, and the sequence is complete and easy to follow: the hand holds both fork and hammer, the hammer visibly strikes the fork once, the fork is carried from the strike position to the water, and the prongs settle into ongoing contact with the surface, with no step skipped, no object swapped out (e.g., a plastic rod standing in for the fork), and contact never happening before the strike.
level_5: Beyond the 4-point sequence, the fork reads clearly as metal (shiny, rigid, opaque, not a dull plastic look), the hammer is visibly its own smaller object with a different shape and material than the fork, the container is shallow enough that the water surface fills most of the lower part of the frame rather than looking like a deep tank, and the same hand performs both the strike and the move-to-water action on screen without any cut to an unseen hand or a different hand appearing partway through.

Scientific and Causal Correctness rubric:
level_1: No observable vibration effect on water; water surface remains completely still before, during, and after contact; or water splashes appear without tuning fork contact or before contact.
level_2: Water surface changes (e.g., ripples or displacement) but not in response to tuning fork contact: e.g., splashes occur only when hammer strikes air, or water moves due to hand shaking unrelated to prong contact.
level_3: Tuning fork contacts water surface, and water exhibits *some* disturbance (e.g., localized ripple, single splash, or brief dimpling), but the disturbance is not dense, not small, not continuous, and does not persist while tuning fork is visibly vibrating (i.e., no clear temporal correlation between visible fork oscillation and water response).
level_4: Tuning fork contacts water surface, and water exhibits *immediate* disturbance upon contact that is (a) composed of multiple small splashes (≥3 discrete splash elements visible simultaneously), (b) appears *only after* contact begins and *while* tuning fork is visibly vibrating (prongs oscillating), and (c) persists as long as contact is maintained and fork vibrates: no delay, no premature cessation, no unrelated motion source.
level_5: All conditions for score 4 are satisfied, and additionally: (a) splashes are *dense* (≥5 simultaneous small splash elements within contact zone), (b) splashes are *uniformly small* (all splash elements visually similar in scale, none larger than prong width), (c) splash activity is *strictly contingent*: begins *exactly at first frame of contact*, ends *exactly at last frame of contact*, and shows no splash when fork is lifted, with zero false positives/negatives in causal timing.

Spatiotemporal Consistency rubric:
level_1: Severe continuity breaks: the fork jumps straight from the strike position to the water's edge with no travel shown in between, the water's level jumps between frames, the hand disappears and reappears, the shadow cast by the hand and fork on the countertop or water flips to a different direction or disappears between frames with no change in the hand's grip or the fork's angle to explain it, or the fork or water flickers or visibly warps.
level_2: Smaller but visible breaks: the fork appears to vibrate while the hand holding it stays perfectly frozen with no supporting motion, the water starts rippling before the prongs ever make contact, the prongs appear to bend in ways rigid metal could not, the container's shape shifts across frames, or the background behind the scene changes inconsistently.
level_3: All objects maintain consistent spatial relationships: hand, fork, hammer, container, and water occupy stable positions relative to each other; the fork moves smoothly from strike location to water; water surface remains level and undisturbed until contact; no object clipping, warping, or transparency glitches; but minor issues exist (e.g., one frame of hand jitter, brief motion blur obscuring contact onset, or a slightly inconsistent shadow cast by the fork's prongs on the water just before contact).
level_4: All spatial relationships remain fixed and coherent: (a) hand, fork, hammer, container, and water occupy stable positions relative to each other; (b) motion paths are smooth and physically plausible (no acceleration spikes, no floating, no unnatural deceleration before contact); (c) the shadow cast by the hand and fork onto the countertop and water surface stays fixed in direction and strength throughout the strike-to-contact sequence; (d) no structural deformation (fork retains rigid shape, water surface retains planar continuity except at splash points).
level_5: Beyond the 4-point continuity, there are no jarring motion artifacts such as skipped frames, ghost trails, or strobing; the fork and hand in the foreground move in sync with the container in the background with no mismatched depth cues; and any small ripple left on the water after the fork lifts away visibly damps down toward calm within a second or two, rather than either lingering indefinitely or vanishing to perfect stillness the instant contact ends.