Two$-$dimensional, steady, low$-$speed flow passes over a symmetric

airfoil. Velocity profiles are measured at the upstream $($surface $1)$ and downstream

$($surface $3)$ locations of the rectangular control volume. The velocity profile at

surface $3$ is measured as follows:

$=\backslash$infty $($

$\backslash$Delta $)$

$1$

$7<=\backslash$Delta

$=\backslash$infty $>=\backslash$Delta

where, $\backslash$Delta $=0\mathrm{.}04$

a$)$ Calculate the mass flow rate passing through surface $4$ using the continuity

equation.

b$)$ Calculate the drag force on the airfoil using the momentum and continuity

equations. $($Note that surface $2($the lower boundary of the control volume$)$ is

a line of symmetry$)$