设加速到速度v时开始减速.
加速：v^2=2a1s1,s1=1/2a1t1^2
减速：v^2=2a2s2,s2=1/2a2t2^2
s=s1+s2
2a1s1=2a2s2
s1/s2=a2/a1
s1/(s1+s2)=a2/(a2+a1)
s1=sa2/(a2+a1)
s2=sa1/(a1+a2)
t1=根号(2s1/a1)=根号(2sa2/a1(a1+a2))
t2=根号(2sa1/a2(a1+a2))
T=t1+t2=根号[2s/(a1+a2)]*[根号a1/a2+根号a2/a1]
=根号[2s/(a1+a2)]*根号a1a2*(1/a2+1/a1)
=根号[2sa1a2/(a1+a2)]*(a1+a2)/a1a2
=根号[2s(a1+a2)/(a1a2)]
好累.