全程：h=h1+h2+h32a1h1=v^2,h1=v^2/2a1,v=a1t1,t1=v/a1减速过程2=-2a2h3=0-v^2,h3=v^2/2a2,0=v-a2t3,t3=v/a2故h2=h-h1-h3=h-(v^2/2a1)-(v^2/2a2)=vt2,得t2=[h-(v^2/2a1)-(v^2/2a2)]/v综上所述：总时间t=t1+t2+t3=v/a...可是答案是h/v+(a2v-a1v)/2a1a2整理一下就可以得出t=h/v+(a2v+a1v)/2a1a2（是加号不是减号）