Answer:
The velocity of the rock when it reaches the ground is
7
m
s
.
Explanation:
The formula we are using is
V
2
2
=
V
2
1
+
2
a
Δ
d
=> Where
V
is the velocity in
m
s
.
=> Where
a
is acceleration in
m
s
2
.
=> Where
Δ
d
is the change in displacement in
m
.
So now we just plug in the numbers.
V
2
2
=
V
2
1
+
2
a
Δ
d
=
0
+
2
(
9.8
)
(
2.5
)
=
√
49
=
7
The velocity of the rock when it reaches the ground is
7
m
s
.
