飞船内部装有喷气发动机,可以向多个方向喷气.根据力的相互性,飞船向前、向后或向旁边喷射高速燃气,获得相反方向的力来改变它的运动状态.例题1“长征”二号F型火箭,它是利用向后喷出气流而使自身受力前进的.当火箭加速升空时,它的机械能变化为A.动能增加,重力势能增加B.动能减少,重力势能减少C.动能不变,重力势能不变 According to the reciprocity of force, the spacecraft injects the high-speed gas forward, backward or sideways to obtain the force in the opposite direction to change its movement state. Example 1 “Long March ”Type II F-type rocket, which utilizes the backward jet of air to force itself forward. As the rocket accelerates its lift, its mechanical energy changes to A. The kinetic energy increases and the gravitational potential increases B. The kinetic energy decreases, the gravity Potential energy to reduce C. kinetic energy unchanged, the same potential of gravity