Question

in real life object ,never travel with uniform velocity , even on a horizontal surface , unless something is done? why is it so ? what is to be done?​

Answer 1

Yes, it is true that object never travels with uniform-velocity in real life. It is so because many unbalanced forces acts upon the object due to which its velocity changes. Gravitational force, frictional force etc. are responsible for this change in velocity.

To make the object move in uniform velocity we have to put a force equal to amount of unbalanced force acting on object so that there creates a balanced force and object will move in a uniform velocity.