
1. p-1 + p-(-3) = 6p = 22.(m-1)/(m-(-3))= 1:33m-3=m+3m= 33.假设是t秒,则:A:1+5tB: -3+2tO: tO 为中点: 1+5t + -3+2t = 2*tt = 2/5即: 0.4秒后,O点恰为AB的中点。

1. p-1 + p-(-3) = 6p = 22.(m-1)/(m-(-3))= 1:33m-3=m+3m= 33.假设是t秒,则:A:1+5tB: -3+2tO: tO 为中点: 1+5t + -3+2t = 2*tt = 2/5即: 0.4秒后,O点恰为AB的中点。