Question

Which is the best example of Newton's First Law of Motion?

Answer 1

Newton's First Law states that an object with no net force on it has an acceleration of zero. There's no good example of that here, but "c" could be the best of a bad lot. "a", "b", and "d" all involve objects that have a net force on them, and thus have a non-zero acceleration. But if the large box in "c" is more difficult to move because you are sliding it, and the force of kinetic friction on it is greater than the force of kinetic friction on the small box, you'll need to apply a greater force on the large box to slide it at constant velocity (zero acceleration).

(Note that if "b" had been a hockey game instead of basketball, I'd have gone with it. But the basketball has the unbalanced force of gravity on it while it is "soaring", so it has a non-zero acceleration, and is not a good example of Newton's First Law.)