COSMOS: Complete Online Solutions Manual Organization System
Chapter 4, Solution 125.
Free-Body Diagram:
Express tension, weight in terms of rectangular components:
uur
IF = ( 75 mm ) i + (1350 mm ) j − ( 250 mm ) k
uur
IF
=T
T=T
IF
=
75i + 1350 j − 250 k
( 75)2 + (1350 )2 + ( − 250 )2
3
54
10
Ti +
Tj−
Tk
55
55
55
(
)
W = − (mg ) j = − ( 7 kg ) 9.81 m/s 2 j = − (68.67 N)j
ΣM B = 0:
− ( 750 mm ) i × A + − ( 375 mm ) i + ( 350 mm ) k × ( − 68.7 N ) j
+ (125 mm ) i + ( 250 mm ) k × T = 0
or
− ( 750 mm ) Ay k + (125 mm ) Az j + ( 375 mm )( 68.7 N ) k + ( 350 mm )( 68.7 N ) i
i
j k
T
+ 125 0 250
( mm ) = 0
55
3 54 −10
continued COSMOS: Complete Online Solutions Manual Organization System
Setting the coefficients of the unit vectors equal to zero:
(a)
i:
−
54
T ( 250 mm ) + ( 68.67 N )( 350 mm ) = 0
55
T = 97.918 N
(b)
k:
or T = 97.9 N
54
− Ay ( 750 mm ) + ( 68.67 N )( 375 mm ) − ( 97.918 N ) (125 mm ) = 0
55
Ay = 50.358 N
j:
10
Az ( 750 mm ) − ( 97.918 N ) (125 mm ) +
55
3
55 ( 97.918 N ) ( 250 mm ) = 0
Az = − 4.7475 N
ΣFx = 0:
Bx +
3
( 97.918 N ) = 0
55
Bx = − 5.3410 N
ΣFy = 0:
50.358 N + B y − 68.67 N +
54
( 97.918 N ) = 0
55
By = − 77.826 N
ΣFz = 0:
− 4.7475 N + Bz −
10
( 97.918 N ) = 0
55
Bz = 22.551 N
Therefore:
A = ( 50.4 N ) j − ( 4.75 N ) k
B = − ( 5.34 N ) i − ( 77.8 N ) j + ( 22.6 N ) k
COSMOS Chapter 4 Solution 125
of 2
Report
Tell us what’s wrong with it:
Thanks, got it!
We will moderate it soon!
Free up your schedule!
Our EduBirdie Experts Are Here for You 24/7! Just fill out a form and let us know how we can assist you.
Take 5 seconds to unlock
Enter your email below and get instant access to your document