24.如圖,在平面直角坐標(biāo)系中,△AOB的頂點(diǎn)O是坐標(biāo)原點(diǎn),點(diǎn)A的坐標(biāo)為(18,24),點(diǎn)B的坐標(biāo)為(50,0),動點(diǎn)P從點(diǎn)B出發(fā)以每秒4個單位長度的速度沿x軸向終點(diǎn)O運(yùn)動,過點(diǎn)P作PC⊥x軸交直線AB于點(diǎn)C,過點(diǎn)C作CD⊥y軸于點(diǎn)D,設(shè)動點(diǎn)P的運(yùn)動時(shí)間為t秒.
?
(1)填空:AO的長為
,AB的長為
;
(2)當(dāng)t=1時(shí),求點(diǎn)C的坐標(biāo);
(3)當(dāng)點(diǎn)C在∠AOB的平分線上時(shí),求動點(diǎn)P的運(yùn)動時(shí)間t的值;
(4)當(dāng)OA平分四邊形OPCD的一邊時(shí),請直接寫出運(yùn)動時(shí)間t的值.