https://blog.gongquiz.com/2020/11/30/%ec%a7%81%ea%b2%bd-100%e3%8e%9c-%ed%96%89%ec%a0%95-150%e3%8e%9c-%ed%9a%8c%ec%a0%84%ec%88%98-600rpm-%ec%b2%b4%ec%a0%81%ed%9a%a8%ec%9c%a8%ec%9d%b4-0-8%ec%9d%b8-2%ea%b8%b0%ed%86%b5-%ec%99%95%eb%b3%b5/