Question: User: Visual Prompt for AI Video Generator:Prompt: A step-by-step interactive 3D problem-solving animation[cite: 16]. Left side shows a simple pendulum with $L = 1.8\text{ m}$[cite: 16]. Calculations appear: $T = 2\pi\sqrt{1.8/9.8} = 2.7\text{ seconds}$[cite: 16]. Next, a second pendulum with $L = 0.36\text{ m}$ appears; the equation solves $T = 2\pi\sqrt{0.36/9.8} = 1.2\text{ seconds}$[cite: 16]. Finally, a comparative animation shows that reducing length to $L/4$ cuts the period in half to $T/2$[cite: 16]. Smooth digital HUD interface with clear mathematical notation.English Voiceover & Text:Voiceover: "Let's apply the formula[cite: 16]. For a pendulum with length $1.8\text{ meters}$, substituting $g = 9.8\text{ m/s}^2$ gives a period of $2.7\text{ seconds}$[cite: 16]. If the string length is $36\text{ cm}$, the period is $1.2\text{ seconds}$[cite: 16]. Notice that to cut the period in half, we must reduce the string length to one-quarter of its original value[cite: 16]!"