25.如圖,已知△ABC中,AC=CB=20cm,AB=16cm,點(diǎn)D為AC的中點(diǎn).
(1)如果點(diǎn)P在線段AB上以6cm/s的速度由A點(diǎn)向B點(diǎn)運(yùn)動(dòng),同時(shí),點(diǎn)Q在線段BC上由點(diǎn)B向C點(diǎn)運(yùn)動(dòng).
①若點(diǎn)Q的運(yùn)動(dòng)速度與點(diǎn)P的運(yùn)動(dòng)速度相等,經(jīng)過1s后,△APD與△BQP是否全等?說明理由;
②若點(diǎn)Q的運(yùn)動(dòng)速度與點(diǎn)P的運(yùn)動(dòng)速度不相等,當(dāng)時(shí)間t為何值時(shí),△APD與△BQP全等?求出此時(shí)點(diǎn)Q的運(yùn)動(dòng)速度;
(2)若點(diǎn)Q以②中的運(yùn)動(dòng)速度從點(diǎn)B出發(fā),點(diǎn)P以原來的運(yùn)動(dòng)速度從點(diǎn)A同時(shí)出發(fā),都逆時(shí)針沿△ABC三邊運(yùn)動(dòng),求經(jīng)過多長時(shí)間,點(diǎn)P與點(diǎn)Q第一次在△ABC的哪條邊上相遇?