FBD of just the pulley first
Now let’s look at member BED:
FBD
0
300
300
0
300
600
600
)
6
(
300
)
3
(
=
+
+

=
=
=


=
=

=
∑
∑
∑
X
X
X
Y
Y
Y
Y
Y
B
B
E
lb
F
lb
B
B
lb
lb
F
lb
E
ft
ft
E
M
Too Many unknowns Move to member FEC
lb
E
ft
lb
ft
E
M
X
X
C
225
0
)
3
(
300
)
4
(
=
=


=
∑
Using this result in the previous equation
lb
B
B
lb
F
X
X
X
75
0
225
300
=
=
+
+

=
∑
Back to Bar FEC
lb
C
C
lb
F
X
X
X
75
0
225
300
=
=
+

=
∑
Member ABC
lb
C
ft
lb
ft
lb
ft
C
ft
lb
M
Y
Y
A
100
0
)
3
(
300
)
4
(
75
)
6
(
)
8
(
75
=
=
+
+


=
∑
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