[问答题]
If the coefficient of k-zq f:/ e sn2d8npy2cz(ke 61jm6prsh u yu0ya;sfz7u, z 0 4m-payi w:3wzof4inetic friction between a 35$-\mathrm{kg}$ crate and the floor is 0.30 , what horizontal force is required to move the crate at a steady speed across the floor? What horizontal force is required if $\mu_{\mathrm{k}}$ is zero?
