A small wind turbine is attached to the superstructure of a ship without a tower to provide some of the electricity used to run the ship. The overall power coefficient is 0.4 and the thrust coefficient is 1.0. The turbine was installed originally to provide power when the ship is stationary in port, but it was suggested that it could be used while the ship is moving. To test if this is possible, consider the following ideal and very favourable situation: if the ship is cruising at speed of 18 knots or 9.2 m/s into a headwind of Uh m/s, what is the minimum value of Uh that results in a net power production by the turbine?