Question

when the object is moving at constant velocity on the rough surface ​

Answer 1

$\bf \red{Answer}$

So using that law if the body is in motion at a constant velocity then the sum of all forces acting on it MUST be zero. It doesn't however means there are no forces acting on the object. If the object is moving on a rough surface then friction between the object and the surface will decelerate the object.

Answer 2

Answer:

if on next is moving with constant velocity then there is no acceleration

I didn't understand what u asked but I have shared what I have understood