飞行物在某有心力场中运动,如果总机械能E0,其轨迹必为椭圆(称为封闭式轨道),且引力源在如其图椭1,圆由一于个有焦心点力上。场是保守力场,机械能角动量均守恒。在讨论中为方便起见,设A和B离引力源所在处的距离统一用r表示,A和B两处的速率统一用v表示,写出A和B处满足的方程:12 The flying object moves in a certain force field. If the total mechanical energy E0, the trajectory must be an ellipse (called a closed orbit), and the gravitational source is in its figure ellipse 1. The circle has a focus on one point. The field is a conservative force field and the angular momentum of mechanical energy is conserved. In the discussion, for the sake of convenience, let A and B be the distance from the source of gravitational force expressed by r, and the rates at both A and B be unified by v, and write the equations satisfied at A and B: 12