This preview shows
page 1. Sign up
to
Chapter 7
209
P7.58
(a)
The new length of each spring is
x
L
2
2
+
, so its extension is
x
L
L
2
2
+
−
and the force it exerts is
k
x
L
L
2
2
+
−
F
H
I
K
toward its
fixed end. The
y
components of the two spring forces add to
zero. Their
x
components add to
F
i
i
= −
+
−
F
H
I
K
+
=
−
−
+
F
H
G
I
K
J
2
2
1
2
2
2
2
2
2
±
±
k
x
L
L
x
x
L
kx
L
x
L
.
FIG. P7.58
(b)
W
F dx
x
i
f
=
z
W
kx
L
x
L
dx
A
=
−
−
+
F
H
G
I
K
J
z
2
1
2
2
0
W
k
x dx
kL
x
L
x dx
A
A
= −
+
+
z
z
−
2
2
0
2
2
1 2
0
e
j
W
k
x
kL
x
L
A
A
= −
+
+
2
2
1 2
2
0
2
2
1 2
0
e
j
b
g
W
kA
kL
kL
A
L
= −
+
+
−
+
0
2
2
2
2
2
2
W
kL
kA
kL
A
L
=
+
−
+
2
2
2
2
2
2
*P7.59
For the rocket falling at terminal speed we have
F
ma
R
Mg
Mg
D Av
T
∑
=
+
−
=
=
0
1
2
2
ρ
(a)
For the rocket with engine exerting thrust
This is the end of the preview.
Sign up
to
access the rest of the document.
- Fall '11
- Staff
- Physics, Force, Mg 3
-
Click to edit the document details
