Awindmill converts wind energy into electricity primarily by using mechanical energy, and mechanical energy is the energy of moving objects. Given these facts, what does a windmill primarily use to convert wind energy into electricty among the following options:
- matter vibrating
 - stored energy
 - solar power
 - batteries
 - Movement of an air mass
 - heat is produced
 - energy of moving objects
 - Something to move


 

       energy of moving objects  