COSMOS: Complete Online Solutions Manual Organization System
Chapter 3, Solution 7.
(a)
M A = xTBFy + yTBFx
= ( 2 m )( 200 N ) sin 60° + ( 0.4 m )( 200 N ) cos 60°
= 386.41 N ⋅ m
or M A = 386 N ⋅ m
(b)
Have
or
M A = xFC
FC =
MA
386.41 N ⋅ m
=
x
2m
= 193.205 N
(c)
∴ FC = 193.2 N
For FB to be minimum, it must be perpendicular to the line joining A
and B
∴ M A = d ( FB )min
with
Then
d =
= 189.454 N
2m
= 78.690°
0.4 m
θ = tan −1
or
.
= 2.0396 m
386.41 N ⋅ m = ( 2.0396 m ) ( FC )min
( FC )min
and
( 2 m )2 + ( 0.40 m )2
( FC )min
= 189.5 N
78.7°