There are two piers A and B, 45 kilometers apart. At 8:00 in the morning, a boat departs from Pier B and goes upstream. At the same time, someone throws a ball from Pier A into the river and goes downstream. The boat is in still water. Traveling 250 meters per minute, when does the boat meet the ball?
有甲、乙两个码头，相距45千米，上午8时，有一船从乙码头出发，逆流而上，同时，有人从甲码头向河中抛下一个皮球，顺流而下，船在静水中每分钟行250米，在几时这只船与皮球相遇？
<result>11</result>