You have only done as much external work on the box as the distance it moves: work = force x distance. If it does not budge no work is done on the object. You have done "internal" work on your muscles which converts to heat energy, but technically speaking, no external work is done on the object
push
Work, more specifically "positive" work because the box moved in the direction in which the force was applied.
Use the formula:Work = force x distance
Yes.
Yes.
negative
thrust from turbines or the pul from propellas
Thrust. The pull of the propellers, the push of the jet engine, the pull of gravity.
friction
In wagon pulling, there is a harnessing system involved which is attached to the breast of the horse. When a horse pulls forward, the harness, which is attached to the wagon moves with him as well, therefore moving the wagon forward.
Yes. The "work" done, in the pure Physics definition, is the force you apply to the box to keep it moving, multiplied by the distance you keep pushing.
On the forward stroke. You naturally push down as you push forward.