GIVEN Air under standard conditions flows through a $4\mathrm{.}0-$mmdiameter drawn tubing with an average velocity of $V=50\frac{m}{s}.$ For such conditions the flow would normally be turbulent. However, if precautions are taken to eliminate disturbances to the flow $($the entrance to the tube is very smooth, the air is dust free, the tube does not vibrate, etc.$),$ it may be possible to maintain laminar flow.

FIND $($a$)$ Determine the pressure drop in a $0\mathrm{.}1-m$ section of the tube if the flow is laminar.

$($b$)$ Repeat the calculations if the flow is turbulent.