PROBLEM 3.138*
Two bolts at A and B are tightened by applying the forces
and couples shown. Replace the two wrenches with a single
equivalent wrench and determine (a) the resultant R,
(b) the pitch of the single equivalent wrench, (c) the point
where the axis of the wrench intersects the xz–plane.
8.00 15.00 26.4 [(152 lb in.) (210 lb in.) (220 lb in.) ]
31.4
246.56 lb in.
ROR
−− −
= ⋅⋅−⋅−⋅
= ⋅
i jk ijk
PROBLEM 3.138* (Continued)
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PROBLEM 3.139*
Two ropes attached at A and B are used to move the trunk
of a fallen tree. Replace the forces exerted by the ropes
with an equivalent wrench and determine (a) the resultant
force R, (b) the pitch of the wrench, (c) the point where the
axis of the wrench intersects the yz–plane.
PROBLEM 3.139* (Continued)
PROBLEM 3.139* (Continued)
PROBLEM 3.140*
A flagpole is guyed by three cables. If the tensions in the
cables have the same magnitude P, replace the forces
exerted on the pole with an equivalent wrench and
determine (a) the resultant force R, (b) the pitch of the
wrench, (c) the point where the axis of the wrench
intersects the xz–plane.
PROBLEM 3.140* (Continued)
PROBLEM 3.141*
Determine whether the force–and–couple system shown can
be reduced to a single equivalent force R. If it can,
determine R and the point where the line of action of R
intersects the yz–plane. If it cannot be so reduced, replace
the given system with an equivalent wrench and determine
its resultant, its pitch, and the point where its axis intersects
the yz–plane.
PROBLEM 3.141* (Continued)
PROBLEM 3.142*
Determine whether the force–and–couple system shown
can be reduced to a single equivalent force R. If it can,
determine R and the point where the line of action of R
intersects the yz–plane. If it cannot be so reduced, replace
the given system with an equivalent wrench and
determine its resultant, its pitch, and the point where its
axis intersects the yz–plane.