if the coefficient of kinetic friction between a 35-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 uk is zero?

Answer 1

For horizontal surfaces,and constant speed,
M*g*uk = F

uk is the kinetic friction coefficient.

Both questions can be answered using that formula. Try it.

In your second question (last sentence), you omitted the word "if" after "required". Be more careful copying your questions.