Answer: F = 0, if you apply a force, the velocity of the object may change.
Explanation: If there is no force of friction or something like that, there is no actual force applied to the object, because it has not any acceleration. This means that the object reached an uniform motion state, this means that the object will move with the constant velocity until a force is applied over it. This is because if there is no force applied, there is no acceleration (by the second Newton's law, we have that F = m*a) and the acceleration is the rate of change of the velocity, so if there is no acceleration, there is no change in the velocity.
This means that the net force required to keep the object moving at 4m/s and un the same direction is zero; F = 0
The net force should be 0 and the same direction should be zero.
In the case when there is no force of friction so there is no actual force applied to the object due to any acceleration. This represents that the object reached a uniform motion state, this represents that the object will move with the constant velocity till a force is applied over it.
learn more about the force here: https://brainly.com/question/1266509
