10/31/2017
1
Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa 1
Ishik University / Sulaimani
Architecture Department
Structure
ARCH 214
Question Bank Chapter -3-
Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa 2
1. Determine the force in each cord for equilibrium of the 200-kg crate. Cord BC remains horizontal due to the roller at C , and AB has a length of 1.5m . Set y=0.75m . 2. If the 1.5-m-long cord AB can withstand a maximum force of 3500N, determine the force in cord BC and the distance y so that the 200-kg crate can be supported.
Problem -1-
Ans:
1.FBA = 3.92 kN
FBC = 3.40 kN
2.FBC = 2.90 kN
10/31/2017
2
3 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -2-
If the mass of the girder is 3 Mg and its center of mass is
located at point G, determine the tension developed in cables
AB, BC, and BD for equilibrium.
Ans:
FBD = 21.5 kN
FAB = 29.4 kN
4 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -3-
If cables BD and BC can withstand a maximum tensile force of 20 kN,
determine the maximum mass of the girder that can be suspended
from cable AB so that neither cable will fail. The center of mass of
the girder is located at point G.
Ans:
m= 2.78 Mg
10/31/2017
3
5 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -4-
1.The members of a truss are connected to the gusset plate. If the forces are concurrent at point O, determine the magnitudes of F and T for equilibrium. Take θ = 30°
2.The gusset plate is subjected to the forces of four members. Determine the force in member B and its proper orientation θ for equilibrium. The forces are concurrent at point O. Take F= 20 kN.
Ans:
1.F=10.2 kN
T=13.3 kN
2.T=14.3 kN
θ = 36.3°
6 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -5-
The members of a truss are connected to the gusset plate. If the
forces are concurrent at point O, determine the magnitudes of F
and T for equilibrium. Take θ = 90º
Ans:
1. F=5.40 kN
T=7.20 kN
10/31/2017
4
7 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
The gusset plate is subjected to the forces of three members.
Determine the tension force in member C and its angle θ for
equilibrium. The forces are concurrent at point O. Take F= 8 kN .
Problem -6-
Ans:
T=7.66 kN
θ = 70.1°
8 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -7-
Determine the stretch in springs AC and AB for equilibrium of the
2-kg block. The springs are shown in the equilibrium position.
Ans:
XAC = 0.793 m
XAB = 0.467 m
10/31/2017
5
9 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -8-
Ans:
m= 8.56 kg
The upstretched length of spring AB is 3 m. If the block is held in
the equilibrium position shown, determine the mass of the block at
D.
10 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -9-
Determine the tension developed in wires CA and CB required for
equilibrium of the 10-kg cylinder. Take θ = 40°
Ans:
FCB =90.4 N
10/31/2017
6
11 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
If cable CB is subjected to a tension that is twice that of cable CA,
determine the angle θ for equilibrium of the 10-kg cylinder. Also,
what are the tensions in wires CA and CB?
Problem -10-
Ans:
FCB =85.2 N FCA =42.6 N θ = 64.3º
12 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -11-
Determine the forces in cables AC and AB needed to hold the 20-
kg ball D in equilibrium. Take F= 300 N and d= 1 m.
Ans:
FAB =98.6 N FAC =267 N
10/31/2017
7
13 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -12-
The ball D has a mass of 20 kg. If a force of F=100 N is applied
horizontally to the ring at A, determine the dimension d so that
the force in cable AC is zero.
Ans:
d= 2.42 m
14 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -13-
If the bucket weighs 50 lb, determine the tension developed in
each of the wires.
Ans:
FED =30.2 Ib FEB =43.6 Ib FBC =69.8 Ib FBA =86.6 Ib
10/31/2017
8
15 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Determine the maximum weight of the bucket that the wire system
can support so that no single wire develops a tension exceeding 100
lb.
Problem -14-
Ans:
W =57.7 Ib
16 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Determine the tensions developed in wires CD, CB, and BA and the
angle θ required for equilibrium of the 30-lb cylinder E and the 60-
lb cylinder F.
Problem -15-
Ans:
FBA =80.7 Ib FCD =65.9 Ib FBC =57.1 Ib θ = 2.95º
10/31/2017
9
17 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -16-
If cylinder E weighs 30 lb and θ = 15º , determine the weight of
cylinder F.
Ans:
FBA = 137.12 Ib WF = 123 Ib
18 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -17-
The cords BCA and CD can each
support a maximum load of 100
lb. Determine the maximum
weight of the crate that can be
hoisted at constant velocity and
the angle θ for equilibrium.
Neglect the size of the smooth
pulley at C.
Ans:
WF = 51 Ib θ = 78.7º
10/31/2017
10
19 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -18-
The wire forms a loop and passes over the small pulleys at A, B, C,
and D. If its end is subjected to a force of P = 50 N, determine
the force in the wire and the magnitude of the resultant force
that the wire exerts on each of the pulleys.
Ans:
T =28.9 N FRAandD = 14.9 N FRBandC = 40.8 N
20 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -19-
The 10-lb weight is supported by the cord AC and roller and by a
spring. If the spring has an unstretched length of 8 in. and the
weight is in equilibrium when d = 4 in., determine the stiffness k
of the spring.
Ans:
k = 6.80 Ib/in
10/31/2017
11
21 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
The spring has a stiffness k = 800 N/m of and an unstretched
length of 200 mm. Determine the force in cables BC and BD when
the spring is held in the position shown.
Problem -20-
Ans:
FBD = 171 N FBC = 145 N
22 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
The pail and its contents have a mass of 60 kg. If the cable BAC
is 15 m long, determine the distance y to the pulley at A for
equilibrium. Neglect the size of the pulley.
Problem -21-
Ans:
Y = 6.59 N
10/31/2017
12
23 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
Problem -22-
The 500-lb crate is hoisted using the ropes AB and AC. Each
rope can withstand a maximum tension of 2500 lb before it
breaks. If AB always remains horizontal, determine the smallest
angle θ to which the crate can be hoisted.
Ans:
θ = 11.5º
24 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
The members of a truss are pin connected at joint O. Determine
the magnitude of F1 and its angle θ for equilibrium. Set F2= 6 kN.
Problem -23-
Ans:
F1= 4.31 N θ = 4.69º
10/31/2017
13
25 Ishik University/Sulaimani Assistant Lecturer/ Asma Ab. Mustafa
The members of a truss are pin connected at joint O. Determine
the magnitudes of F1 and F2 for equilibrium. Set θ = 60º.
Problem -24-
Ans:
F1= 1.83 N F2= 9.60 N
Top Related