A square aluminum (shear modulus is \( 25 \times 10^{9} \, \text{N m}^{-2} \)) slab of side \( 60 \, \text{cm} \) and thickness \( 15 \, \text{cm} \) is subjected to a shearing force (on its narrow face) of \( 18.0 \times 10^{4} \, \text{N} \). The lower edge is riveted to the floor. The displacement of the upper edge is ______ \( \mu \text{m} \).
