# Lift me up, lift

**Classical Mechanics**Level 5

One of the proposed mechanisms for the lift of an aircraft is the pressure difference that develops due to the aerodynamic shape of the wings. Higher pressure develops below the airplane which lifts it up. Suppose you have a wings with a semi-circular cross-section of radius \(1~\mbox{m}\). If air molecules need \(1 ~\mbox{s}\) to go from one edge of the wing to another and meet again, what is the pressure difference **in \(\frac{\mbox{N}}{\mbox{m}^2}\)** that pushes the wing up?

**Details and assumptions**

- The density of air is \(1.23~\mbox{kg/m}^3\)
- Neglect the hydrostatic pressure

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