A steam engine runs at 150 r.p.m. Its turning moment diagram gave the following area measurements in mm taken in order above and below the mean torque line: 500, 250, 270, 390, 190, 340, 270, 250 The scale for the turning moment is 1 mm = 500 N-m, and for crank angle is Imm = 5. The fluctuation of speed is not to exceed +1.5% of the mean, determine the cross-section of the rim of the flywheel assumed rectangular with axial dimension equal to 1.5 times the radial dimension. The hoop stress is limited to 3 MPa and the density of the material of the flywheel is 7500 kg/m?.