A uniform block of granite in the shape of a book has face dimensions of 23.0 centimeter and 23.6 centimeter and a thickness of 1.97 centimeter. The density (mass per unit volume) of granite is 2.64 g/cm3. The block rotates around an axis that is perpendicular to its face and halfway between its center and a corner. Its angular momentum about that axis is 0.607 kg·m2/s. Obtain its rotational kinetic energy about that axis?