[单选题]
A wooden block slides directly d mi66;tyc3n k34k0ezj0 cvaylown ayyydm ubt ,9b* gi8e8e1 /wys+n inclined plane, at a constant velocity of 6.0 m b b*9wiy 1myu88y/tsdge,y+e/s. What is the coefficient of kinetic friction, if the plane makes an angle of $25^{\circ}$ with the horizontal?
