Take for example the dentist's drill. A model jet engine turns at 100,000 rpm, while a drill turns at 260,000 to 400,000 rpm. Moreover, a drill gives off no heat, only water and air.
以牙醫的「手機」來說，模型飛機的噴射引擎一分鐘轉速達到十萬轉，而手機轉速卻高達二十六至四十萬轉，而且完全不發散熱氣，只噴出水和空氣。