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                                                                                                                                             木芙蓉
                                                                                                                                        南宋•吕本中
                                                                                                                    小池南畔木芙蓉，雨后霜前着意红。
                                                                                                                     犹胜无言旧桃李，一生开落任东风。

如图中最后一秒的加速度为____ m/s²．