这道题目怎么解？液压方面的

A piston 20mm in diameter is moving downwards under a force of 150n,which forces the oil in the hydraulic cylinder out to the atmosphere through a narrow gap . Assume that the piston and the cylinder tube are set inline and the gap length is 70mm, and the oil dynamic viscosity is 0.05Pa.s . How long would it experience for the piston to drop down by 0.1m？

大哥，整点汉语好不，我看不懂啊，我还是先去问问你这英语是咋翻译的。