如圖,在直角坐標(biāo)系中,矩形OABC的頂點(diǎn)O與坐標(biāo)原點(diǎn)重合,頂點(diǎn)A,C在坐標(biāo)軸上,OA=60cm,OC=80cm.動(dòng)點(diǎn)P從點(diǎn)O出發(fā),以5cm/s的速度沿x軸勻速向點(diǎn)C運(yùn)動(dòng),到達(dá)點(diǎn)C即停止.設(shè)點(diǎn)P運(yùn)動(dòng)的時(shí)間為ts.
(1)過(guò)點(diǎn)P作對(duì)角線OB的垂線,垂足為點(diǎn)T.求PT的長(zhǎng)y與時(shí)間t的函數(shù)關(guān)系式,并寫(xiě)出自變量t的取值范圍;
(2)在點(diǎn)P運(yùn)動(dòng)過(guò)程中,當(dāng)點(diǎn)O關(guān)于直線AP的對(duì)稱點(diǎn)O′恰好落在對(duì)角線OB上時(shí),求此時(shí)直線AP的函數(shù)解析式;
(3)探索:以A,P,T三點(diǎn)為頂點(diǎn)的△APT的面積能否達(dá)到矩形OABC面積的
?請(qǐng)說(shuō)明理由.