They store the energy mechanically by rotating mass around an axis.

它们通过质量绕轴旋转机械存储能量。

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This means an overall reduction of the weight and, above all, a rotation of the rotating mass, and has therefore further increased the reactivity of both wheels.

这也使得总重量进一步减轻。然而，其最重要的意义在于减少了轮组转动惯量，这意味着轮组的转动变化反应更加迅速。

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So, for two skaters of the same mass rotating at the same speed, the one with its mass more extended in space will have the greater angular momentum.

因此，对于以相同速度旋转的两个同质量选手来说，肢体在空间中更为外扩的那个选手将具备更大的角动量。

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Support was maintained through consecutive mass meetings rotating from church to church around the city.

NEWYORKER: Small Change