An object of mass 5 kilograms is moving across a surface ima straight line with a speed of3.5 meters/second. What amount would be required to keep the object in motion if you ignore the surface friction

None

Explanation:

Newton's First Law states that an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an external force.

There is no surface frictional force, so the object will keep moving with a speed of 3.5 m/s without additional assistance.