Painting with a Bouncing Ball: Dynamic Coordinate Art

① This example demonstrates a ball bouncing within a rectangular boundary, leaving a colorful trail that creates a dynamic painting effect. ② Core mathematical concepts include coordinate geometry, vectors, linear transformations (reflection and translation), and conditional logic for bounce handling. ③ Construction highlights: GeoGebra commands such as Vector (defining velocity), Circle (creating the ball), OrthogonalLine and Mirror (for wall reflection), Translate (for movement), and SelectedIndex (for color switching) are used; objects include coordinate bounds (xmin, xmax, ymin, ymax), walls, velocity components (vx, vy), a speed slider, and buttons for start/pause/reset. ④ Suitable for middle school to early high school students, this interactive tool helps visualize vector motion, reflection, and coordinate systems, and can serve as an engaging introduction to programming concepts or as a creative math-art activity.