25．（1）设A与B碰前速度为v₀，由  

由上式

同理                                                                          ⑥

                                                                    ⑤

                                                                            ④

（2）由于液滴从B板边缘飞出，利用平抛规律有：          ③

由①②得

由于平衡                                                               ②

24．（1）   ∴                                    ①

二阶段     ∴