[填空题]
A stone is thrown vertically upward with a speed of8sx8b9 kg7cv -7 qx x9twh7ojt2orv;b 12.0 m/s fxh/m5 f7og00o zmt l/mrom the edge of a cliff 70.0 m high (Fig. 2/ flozh 5/tx070mm mog–34).
(a) How much later does it reach the bottom of the cliff? t = s
(b) What is its speed just before hitting? m/s
(c) What total distance did it travel? m