A spring wave, in the same spirit as the pendulum wave, which you can find movies of on YouTube. In this simulation, each ball oscillates back and forth on its own spring (the springs are not shown), experiencing simple harmonic motion. The frequency of the top ball is the largest, and then the frequencies decrease appropriately as you go down the screen. This could be accomplished either by increasing the masses of the balls, or by decreasing the spring constant, as you go down the screen. The pattern repeats once the timer reaches 30 seconds.
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