A2-kg objects is moving horizontally with a speed of 4 m./s. how much net force is required to keep the object moving with the same speed and in the same directions

Look at Newton's Second Law of Motion.  F = m A

No, I mean REALLY LOOK AT IT.

The FORCE you need to give something an acceleration of A is          (MASS) x (A).

If your object is moving with a steady speed in a straight line, then it has no acceleration.  A = Zero.

The force it takes to keep it moving that way is (mass) x (zero) = Zero .

An object that's moving in a straight line at a steady speed doesn't need ANY force to keep going.

Force does not CAUSE constant uniform motion. Force CHANGES motion.

(75°f − 32) × 5/9 = 23.889°c