An ellipse on a non-slip inclined plane can rock, roll, or jump. Below a threshold energy, it rocks about its static equilibrium configuration. Above this energy, it rolls, and, if it rolls, it will eventually jump off the incline after some number of rolls. It is shown that jumping can only occur in certain configurations of the ellipse.

中文翻译：

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椭圆的摇滚

防滑斜面上的椭圆可以摇动、滚动或跳跃。低于阈值能量，它会围绕其静态平衡配置摇摆。超过这个能量，它会滚动，如果它滚动，它最终会在一定次数的滚动后跳下斜坡。结果表明，跳跃只能发生在椭圆的某些配置中。