A.0.5m/s B.1.5m/s C.2.4m/s D.4m/s E.3m/s
A.1~2㎝ B.2~3㎝ C.3~4㎝ D.5~6㎝ E.7~8㎝
A.1~3㎝ B.4~6㎝ C.7~10㎝ D.10~15㎝ E.15~20㎝