FIGURE 17-2 -Two Identical Concrete Slabs Lie Flat and in Contact with in Contact

Multiple Choice

FIGURE 17-2
-Two identical concrete slabs lie flat and in contact with each other as shown in Fig. 17-2. If the temperature increases by 40°C, the lower edges opposite the contact edges remained fixed in position, and the lower edges of the contact side remain in contact, at what angle φ will the slabs be tilted? The coefficient of thermal expansion of the concrete is 10 × 10^-6/K.

A) 18.7°
B) 0.0283°
C) 14.5°
D) 1.62°
E) answer depends on length of slabs