Question

Using your hand to exert a horizontal force, you push a physics textbook across the floor at a steady pace. the frictional force exerted by the floor on the book opposes its motion. is the “push” force exerted by your hand greater than, less than, or equal to that frictional force?

Answer 1

Since the book moves at a constant speed its acceleration is zero.  Using Newton's 2nd law F=ma, where a is zero in constant velocity, requires that F=0.  Since the forces are in different directions and sum to zero, the forces are equal and opposite.  So the push is exactly equal to the friction force.