A two bladed wind-turbine with total mass 120kg (60kg per blade) and rotor diameter 20m is spun up from rest to an angular speed of /60T radians per second in 30 full revolutions of the blades (i.e. 0 = 60 radians). %3D The (constant) torque exerted by the wind on the turbine is O 1000 Nm An answer not listed 4000 Nm 2000 Nm O 3000 Nm