物理学 第五版 4-3角动量角动量守恒定律 dL M dt 作用于质点的合力对参考点O 的力矩,等于质点对该点O的角 动量随时间的变化率 The torque with respect to reference point o ofthe combined force on a mass point is equal to the change rate with respect to time of the angular momentum of the mass point with respect to point O 第四章刚体的转动 5/344-3 角动量 角动量守恒定律 第四章 刚体的转动 物理学 第五版 5/34 t L M d d   = 作用于质点的合力对参考点 O 的力矩 ，等于质点对该点 O 的角 动量随时间的变化率. The torque with respect to reference point O of the combined force on a mass point is equal to the change rate with respect to time of the angular momentum of the mass point with respect to point O