Domain: Natural Science — Physics
Target concept: Use a pipette to blow air at the cart on the horizontal table, verifying that the cart moves in the direction of the airflow, and that the harder the blowing, the faster the cart moves, exhibiting a noticeable visual difference.

Video generation prompt: Place a stationary toy car on a horizontal table. Hold a straw behind the car and blow air towards it to make the car move forward. First, blow gently, then blow with more force.

Evaluation guide:
(i) Target concept: Newtonian force transmission via fluid (air) momentum transfer to solid object; minimum mechanism: air must be directed from behind the car to push it forward, and differential blowing intensity must produce differential net force, resulting in measurably distinct accelerations and displacements.
(ii) Storyline: [Frame 0] Stationary car centered on table, straw held motionless behind it; [Frame 1–N] Gentle blow begins → visible mouth/cheek cue → car initiates forward motion → motion progresses then halts completely; [Frame N+1–M] Silence/pause → forceful blow begins → stronger mouth/cheek cue → car initiates forward motion again → motion progresses farther than before → halts completely; all events observed from fixed frontal/side angle showing full car, straw, and table surface without occlusion.

Manual:
Experimental Procedure
1. Place a stationary toy car on a horizontal table.
2. Hold a straw horizontally behind the car, aligned with its rear.
3. Blow gently through the straw — observe car movement.
4. After car stops, blow forcefully through the straw — observe car movement.
Observation of Experimental Phenomena
- Car remains still before each blow.
- Car moves forward only after each blow begins.
- First motion is shorter and slower; second motion is longer and faster.
Summary of Experimental Principles
- Airflow exerts force on the car.
- Greater airflow speed (harder blow) produces greater force, resulting in greater acceleration and displacement.

Prompt Grounding rubric:
level_1: No toy car present on horizontal surface; no straw visible; no blowing action depicted; no sequence of gentle then forceful blowing; scene does not show a tabletop setting.
level_2: Toy car and horizontal table are present, but straw is absent or incorrectly positioned (e.g., in front of the car, not behind); blowing action is implied but no visible airflow indicator (e.g., no mouth motion, no puff effect); only one blowing intensity is shown, not two distinct intensities.
level_3: Toy car placed stationary on horizontal table; straw held visibly behind the car; two discrete blowing actions occur in sequence — first gentle (mouth slightly open, minimal facial effort), second forceful (mouth wider, cheeks visibly engaged); car remains initially still before the first blow and moves forward after each blow.
level_4: All of score 3, AND straw orientation is consistently rear-aligned (parallel to table surface, pointing directly at the car's rear); car movement begins only after each blow onset (no pre-movement or drift); no extraneous objects (e.g., hands holding the car, secondary tools) interfere with the core setup.
level_5: All of score 4, AND the two blows are visually differentiated by clear cues in the blowing action itself: the mouth opens wider and the cheeks show more effort on the second blow than the first; AND the straw is held at the same height and distance behind the car for both blows (no repositioning between them), so any difference in the car's motion can be attributed to blowing force rather than a change in setup; AND there is no pause, reversal, or hesitation within either individual motion.

Scientific and Causal Correctness rubric:
level_1: Car moves backward, sideways, or rotates without forward translation; car moves before any blowing action; car moves continuously without correlation to blowing; airflow direction contradicts motion (e.g., straw aimed away from the car yet the car still moves forward).
level_2: Car moves forward but violates the causal chain: motion occurs before the blow starts, or continues after the blow ends without decay; the car moves during both blows but displacement magnitude is identical across intensities; no discernible difference in motion onset timing or extent between the gentle and forceful blows.
level_3: Car is stationary before the first blow; moves forward only after the first blow begins; moves forward again only after the second blow begins; the second motion starts later than the first (i.e., after the first motion stops) and covers visibly greater distance than the first motion.
level_4: All of score 3, AND car motion is exclusively forward (no lateral wobble, tilt, or rotation); no spontaneous motion between blows; motion ceases fully before the second blow begins; the car remains on the table surface throughout (no lift-off, tipping, or falling off).
level_5: All of score 4, AND the car's motion begins immediately after the blow cue is visible, with no perceptible pause or delay a viewer could point to between the blow and the first movement; the car comes fully to rest before the next blow begins; the second displacement is clearly larger than the first, along the same straight-line direction, with no sideways drift.

Spatiotemporal Consistency rubric:
level_1: The car appears to teleport to a new spot instead of moving there continuously; the tabletop changes texture, color, or reflectivity mid-clip; the room lighting jumps abruptly (e.g., the car's shadow disappears and then reappears in a different spot); the straw or the hand holding it flickers or disappears momentarily; or the car itself changes size or color between frames.
level_2: The car's motion is jittery or skips between positions rather than gliding smoothly; the table edge or background flickers or tears; the hand holding the straw shakes so much the framing becomes unstable; or the car appears to clip through itself or the table due to an inconsistent viewing angle.
level_3: The car moves with smooth, continuous progression across the table; the tabletop itself stays flat and unchanging; the straw stays in the same position behind the car's rear across both blows; there is no flickering, popping in/out, or visible distortion of the car, straw, or table.
level_4: All of score 3, AND the camera holds one fixed viewpoint (no pan, tilt, or zoom); the car's wheels visibly turn in sync with its forward movement rather than sliding or staying still while the car moves; the hand and straw keep a stable, physically plausible position relative to the car with no floating or stretching.
level_5: All of score 4, AND the car's speed changes smoothly at the start and end of each motion with no sudden jump or freeze; the wheels visibly spin faster during the second, stronger motion than during the first; the car and table keep a consistent size, depth relationship, and overlap with the background throughout the clip.