Avariable mesh screen produces a linear and axisymmet- ric velocity profile as indicated in fig. p5.50 in the air flow through a 2-ft-diameter circular cross-sectional duct. the static pressures upstream and downstream of the screen are 0.2 and 0.15 psi and are uniformly distributed over the flow cross-sectional area. neglecting the force exerted by the duct wall on the flow- ing air, calculate the screen drag force.