解题思路:
(1)上升阶段:
−
V
2
0
=
−
2
g
h
,则
V
0
=
=
"
3
m
/
s
"
(2)上升阶段:
0
=
V
0
−
g
t
1
自由落体阶段:
h
0
+
h
+
H
=
g
t
2
2
故:
t
=
t
1
+
t
2
得:
t
=
1.8
s
(1)3m/s (2)1.8s
<>
解题思路:
(1)上升阶段:
−
V
2
0
=
−
2
g
h
,则
V
0
=
=
"
3
m
/
s
"
(2)上升阶段:
0
=
V
0
−
g
t
1
自由落体阶段:
h
0
+
h
+
H
=
g
t
2
2
故:
t
=
t
1
+
t
2
得:
t
=
1.8
s
(1)3m/s (2)1.8s
<>