Question:
Near the ground, wind speed can be modeled as proportional to height above the ground. (This is a reasonable assumption for small heights.) A wind turbine converts a constant fraction of the available kinetic energy into electricity. The conditions are such that when operating at 10m above the ground,the turbine delivers 15kW of power. How much power would the same windmill deliver if it were operating at 20m above the ground?
(A) 15kW.
(B) 21kW.
(C) 30kW.
(D) 60kW.
(E) 120kW.