63. We choose
down
as the +
y
direction and place the coordinate origin at the top of the
building (which has height
H
). During its fall, the ball passes (with velocity
v
1
) the top of
the window (which is at
y
1
) at time
t
1
, and passes the bottom (which is at
y
2
) at time
t
2
.
We are told
y
2
–
y
1
= 1.20 m and
t
2
–
t
1
= 0.125 s. Using Eq. 215 we have
y
y
v
t
t
g t
t
2
1
1
2
1
2
1
2
1
2
−
=
−
+
−
b
g
b
g
which immediately yields
(
)
(
)
2
2
1
2
1
1.20 m
9.8 m/s
0.125 s
8.99 m/s.
0.125 s
v
−
=
=
From this, Eq. 216 (with
v
0
= 0) reveals the value of
y
1
:
2
2
1
1
1
2
(8.99 m/s)
2
4.12 m.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '06
 Stoler
 Physics, m/s, coordinate origin, +y direction

Click to edit the document details