COSMOS: Complete Online Solutions Manual Organization System
Chapter 3, Solution 92.
Have ΣF :
where TCD
TCD = F
JJJG
CD
= TCD
CD
= ( 61 lb )
− 0.9i − 16.8j + 7.2k
( − 0.9 )2 + ( −16.8)2 + ( 7.2 )2
= − ( 3 lb ) i − ( 56 lb ) j + ( 24 lb ) k
So that
F = − ( 3.00 lb ) i − ( 56.0 lb ) j + ( 24.0 lb ) k
Have ΣM O = rC/D × TCD = M
i
j
k
0 22.5 0 lb ⋅ ft = M
− 3 − 56 24
∴ M = ( 540 lb ⋅ ft ) i + ( 67.5 lb ⋅ ft ) k
M = ( 540 lb ⋅ ft ) i + ( 67.5 lb ⋅ ft ) k
.