24.如圖,在Rt△ABC中,∠ABC=90°,AB=4,BC=3,點(diǎn)D為AC邊上的動(dòng)點(diǎn),點(diǎn)D從點(diǎn)C出發(fā),沿邊CA往A運(yùn)動(dòng),當(dāng)運(yùn)動(dòng)到點(diǎn)A時(shí)停止,若設(shè)點(diǎn)D運(yùn)動(dòng)的時(shí)間為t秒,點(diǎn)D運(yùn)動(dòng)的速度為每秒1個(gè)單位長(zhǎng)度.
(1)當(dāng)t=2時(shí),分別求CD和AD的長(zhǎng);
(2)當(dāng)t為何值時(shí),△CBD是直角三角形?
(3)若△CBD是等腰三角形,請(qǐng)直接寫出t的值.