vo²=2as
vo²-v1²=2a×2/3s,v1²=1/3×2as=1/3vo²,则Vo-at1=根号下1/3 vo,t1=（1-根号1/3）vo/a
vo-at2=1/3vo,t2=(1-1/3)v0/a
则t1/t2=(1-根号1/3):(1-1/3)