E=(1/2mv0)2+(mv)2-(3/2mv3)2，损失能量E=5mv02/要使刚好不穿出;v=0根据动能定理得：mv0=2mv1+mv0/ v1=v0/16;mv0+2mv=3mv3;4; 该过程损失的能量E=5mv02/16.2v0;2
