24.如圖1,在矩形ABCD中,AB=3,AD=6,點(diǎn)E在邊BC上,且BE=2.動(dòng)點(diǎn)P從點(diǎn)E出發(fā),沿折線EB-BA-AD以每秒1個(gè)單位長(zhǎng)度的速度運(yùn)動(dòng),作∠PEQ=90°,EQ交邊AD或邊DC于點(diǎn)Q,連接PQ.當(dāng)點(diǎn)Q與點(diǎn)C重合時(shí),點(diǎn)P停止運(yùn)動(dòng).設(shè)點(diǎn)P的運(yùn)動(dòng)時(shí)間為t秒.(t>0)
(1)當(dāng)點(diǎn)P和點(diǎn)B重合時(shí),直接寫(xiě)出點(diǎn)P的運(yùn)動(dòng)時(shí)間為
秒和線段PQ的長(zhǎng)為
;
(2)當(dāng)點(diǎn)Q和點(diǎn)D重合時(shí),求線段PQ的長(zhǎng);
(3)如圖2,當(dāng)點(diǎn)P在邊AD上運(yùn)動(dòng)時(shí),求證:
的值為定值.