A rugged instrument used frequently for monitoring gas velocity in smoke stacks consists of two open tubes oriented to the flow direction as shown and connected to a manometer. The pressure coefficient is 1.0 at A and -0.3 at B. Assume that water, at 20C, is used in the manometer and that a 5mm deflection is noted. The pressure and temperature of the stack gases are 101 kPa and 250C. The gas constant of the stack gases is 200J/kg*K. Determine the velocity of the stack gases.