Steam flows steadily and isentropically through a nozzle. At an upstream section where the speed is negligible, the temperature and pressure are \(450^{\circ} \mathrm{C}\) and \(6 \mathrm{MPa}\) absolute. At a section where the nozzle diameter is \(2 \mathrm{~cm}\), the steam pressure is \(2 \mathrm{MPa}\) absolute. Determine the speed and Mach number at this section and the mass flow rate of steam. Sketch the passage shape.