Solution Manual for Vector Mechanics for Engineers: Statics - Chapter 7 (Internal Forces)

CHAPTER7
V

, PROBLEMV7.1

DetermineVtheVinternalVforcesV(axialVforce,VshearingVfor
ce,VandVbendingVmoment)VatVPointVJVofVtheVstructureV
indicated.

FrameVandVloadingVofVProblemV6.76.



SOLUTION

FromVProblemV6.76:
CVxV =V720
Vlb

CyV =V140Vlb




FxV =V FV −V720VlbV =V0
0:
FV =V+720V FV=V720Vlb ◀
lb
FyV =V
0: V −140 lb = 0
VV =V140Vlb VV=V140.0Vlb
◀
MV −V(140Vlb)(8Vin.)V=V0

MV =V+1120VlbV MV=V1120VlbVVin.
in. ◀




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HillVEducation.VPermissionVrequiredVforVreproductionVorVdisplay.

, PROBLEMV7.2

DetermineVtheVinternalVforcesV(axialVforce,VshearingVforce,VandVbe
ndingVmoment)VatVPointVJVofVtheVstructureVindicated.

FrameVandVloadingVofVProblemV6.78.




SOLUTION

FromVProblemV6.78:
CV=V30
Vlb




FxV =V0:V V −V FV +V120VlbV =
V0
FV=V120.0Vlb ◀
FV =V+120V
lb

FyV =V0:V V −VVV +V30VlbV=V VV=V30.0Vlb
0 ◀
M J V =V0:V V MV +V(30Vlb)(4Vin.)V−V(120Vlb)(2
)
Vin. V=V0


MV=V120.0VlbVVin.
◀




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, PROBLEMV7.3

DetermineVtheVinternalVforcesVatVPointVJVwhenV=V90°.




SOLUTION

ReactionsV(V=V90
)
MAV =V0:V V BVy
= 0
V13

AV=V845V AV=V845
N N
5V
FxV =V0:V V (845VN)V x +V
13
BxV =V −325 BVxV =V325
FBDVBJ VN VN
:
FV =V0 125VNV−VFV FV=V125.0 67.4°◀
: =V0 VN
22.6°V
FV =V V − 300 N V = 300 ◀
0: (325VN)(0.480Vm)V−VMV =V0

MV =V+156VNm
M = 156.0 Nm




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HillVEducation.VPermissionVrequiredVforVreproductionVorVdisplay.