1. The power of the wind

Consider a moving air mass with velocity V . A volume of air of length L parallel to the direction of the wind and of area S is characterised by:

• a linear momentum SLρV ;

• a kinetic energy of 1/2 SLρV ² where ρ is the density of the air.

To calculate the power passing over an area S perpendicular to the direction of the wind we can say L  =  V . Therefore the power of...