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.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.