The truncated nozzle shown in the figure below is used to monitor the mass-flow rate of air in a pipe. The area of the nozzle is 3 cm2. The total pressure and total temperature measured upstream of the nozzle in the pipe are 300kPa absolute and 20°C. The pressure downstream of the nozzle (back pressure) is 90 kPa. Absolute. Calculate the mass-flow rate.