$1$

Air density: $1\mathrm{.}1k\frac{kg}{m^3}$

Exit velocity: $90\frac{m}{s}$

Freestream Velocity: $40\frac{m}{s}$

Area swept by the propeller: $4m^2$

Efficiency: $0\mathrm{.}85$

Calculate the Power $($W$).$

$2$

Air density: $0\mathrm{.}8k\frac{g}{m^3}$

Thrust: $4000$ N

Efficiency: $0\mathrm{.}85$

Freestream Velocity: $80\frac{m}{s}$

Area swept by the propeller: $5m^2$

Calculate the exit velocity.