Question

what force is acting on an object of mass 1 kg moving with a constant velocity

Answer 1

We assume, all friction and drag is absent. Then we say, for a body to continue to accelerate it requires a force or else it will move uniformly (Newton’s law of inertia, disproving Aristotle’s falacy that a body requires fkrce to move uniformly), since acceleration is zero, net force (sum total of all forces acting on body ; say, hypothetically may or may not be) is zero. Therefore by F= ma, since a=0, F = 0.

If we say (just for fun), friction acts that means a constant frictional force causes it to gradually slow down, to reverse that a force equal to the frictional force in magntitude and in direction of motion must act so that the net forces cancel each other out and body koves uniformly.

Cheers!