如圖,在Rt△ABC中,∠ACB=90°,AC=4,BC=3,動(dòng)點(diǎn)P從點(diǎn)A出發(fā)沿AC方向以每秒5個(gè)單位長(zhǎng)度的速度向終點(diǎn)C運(yùn)動(dòng),當(dāng)點(diǎn)P不與點(diǎn)A、C重合時(shí),過(guò)點(diǎn)P作PQ⊥AB于點(diǎn)Q,將線段PQ繞點(diǎn)P逆時(shí)針旋轉(zhuǎn)90°得到線段PR,連接QR.設(shè)點(diǎn)P的運(yùn)動(dòng)時(shí)間為t秒.
(1)線段AP的長(zhǎng)為
5t
5t
(用含t的代數(shù)式表示).
(2)當(dāng)點(diǎn)R落在BC邊上時(shí),求t的值.
(3)當(dāng)C、R、Q三點(diǎn)共線時(shí),求t的值.
(4)當(dāng)△CPR為鈍角三角形時(shí),直接寫出t的取值范圍.