单项选择题
质点动量定理说的是, The Particle Momentum Theorem says,
A、一段时间内外力作用的冲量等于质点动能的增量; The Impulse of internal and external forces over a period of time is equal to the increment of Kinetic Energy of the Particle;
B、一段时间内外力作用的冲量等于质点势能的增量; The Impulse of the internal and external force over a period of time is equal to the increment of the Potential Energy of the Particle;
C、一段时间内外力作用的冲量等于质点机械能的增量; The Impulse of internal and external force over a period of time is equal to the increment of Mechanical Energy of the Particle;
D、一段时间内外力作用的冲量等于质点动量的增量; The Impulse of internal and external force over a period of time is equal to the increment of Momentum of the Particle;