A 4kg object is moving across a friction free surface with a constant velocity of 2ms. Which one of the following horizontal forces is necessary to maintain this motion Explain using Newton's law?

Answer:
No force is required to maintain motion at a constant speed in a staright line,
if there is no friction or other dissipative force working against it.
First answer by Alcohen2006. Last edit by Alcohen2006. Contributor trust: 1135 [recommend contributor recommended]. Question popularity: 1 [recommend question].