英语翻译A dock worker loading crates on a ship finds that a 12 k

英语翻译
A dock worker loading crates on a ship finds that a 12 kg crate,initially at rest on a horizontal surface,requires a 69 N horizontal force to set it in motion.However,after the crate is in motion,a horizontal force of 54 N is required to keep it moving with a constant speed.
The acceleration of gravity is 9.8 m/s2 .Find the coefficient of static friction between crate and floor.
Find the coefficient of kinetic friction.