[填空题]
A stone is dropped from the roof ofd ftx4ec).2 uy a b6gvro(zny/r 3uilding; 2.00 s after that, a second stone is thrown strn r(/gvzy63 oraight down with an initial speed of 25.0 m/s and the two stones land at the same time.
(a) How long did it take the first stone to reach the ground? $t_1$ = s
(b) How high is the building? m
(c) What are the speeds of the two stones just before they hit the ground? #1 m/s #2 m/s