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2005 Term 1 Quiz 1

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EG1109 Statics and Mechanics of Materials Quiz 1
(2005/06 Semester 1)
Question 1
The sign’s weight Ws = 160 N acts at the point shown in Figure Q1. The 50 N weight of the
bar AD acts at the midpoint of the bar. Determine the tension in the cable AE and the reactions
at D .
0.15 m
0.60 m
0.25 m
E
30o
20o
A
B
WALL
Bicyle
Rentals
Ws
C
D
0.65 m
Figure Q1
T = 145.8 N #(ANS)
Dx = 137 N #(ANS)
D y = 160.1 N #(ANS)
Question 2
The roof truss in Figure Q2 is subjected to wind load which may be modeled as concentrated
loads acting perpendicular to the windward side at joints A, E and F . The magnitudes of the
loads are as shown in Figure Q2. Determine the forces in members CD , DE and CG.
Triangle CDF is an equilateral triangle and joints E and G are at the midpoints of their respective
sides.
10 kN
F
8 kN
5 kN
G
E
3m
C
D
B
A
3m
2m
3m
Figure Q2
FCD = 20.2 kN (Tension) #(ANS)
FCG = 0 kN
#(ANS)
FDE = 10.4 kN (Compression)
#(ANS)