OUESTION 3 a) The horizontal steel rod, 2.5 m long and
1200mm^(2)
in cross-sectional area, is securbs, between two walls as shown in Figure Q3a. If the rod is stress-free at
20\deg C
, compule the stress when the temperature has dropped to
-20\deg C
. Assume that the walls do not move. [2 marks] b) The rigid bar of negligible weight is pinned at
O
and attached to two vertical rods as shown in Figure Q3b. Assuming that the rods were initially stress-free. If
P=20
kN
, determine: i. The normal stresses in each of the members ii. The vertical deflection of the
A
. [8 marks] Figure Q3b