问题如图所示,A是山脚,B是山顶,C是山坡上的一点,AC=1/3AB,甲、乙二人同时从山脚出发,到达山顶,再返回山脚,如此往返运动,中间没有停留.已知甲乙上山速度之比是6:5,并且他们下山速度都是各自上山速度的1.5倍.出发一段时间后,甲第1次在山顶看见乙在AC段向上爬;又经过一段时间后,甲第2次在山顶看见乙在AC段向上爬.问:当甲第2次在山顶看见乙在AC段向上 The problem is shown in the figure, A is the foot of the mountain, B is the top of the mountain, C is a little on the hillside, AC = 1 / 3AB, A, B two at the same time starting from the foot of the mountain to reach the top of the mountain and then back to the foot, so back and forth movement, Stop .Bars A and B are known to speed ratio is 6: 5, and they are down the mountain speed is 1.5 times their respective speed.After some time off, A first saw the top of the hill in the AC section to climb; and after a period of time After A, on the top of the mountain in the second saw B to climb in the AC segment. Q: When A second saw the top of the hill in the AC segment upward