A sledge on which you are riding is given an initial push to slide on a straight level frictionless track. Snow is falling vertically on the sledge in the frame of the track. You have to adopt any one of the following three strategies to keep our sledge moving fastest.
I) You sweep the snow off the sledge so that it leaves the sledge perpendicular to the track, as seen by you in the frame of the sledge.
II) You sweep the snow off the sledge so that it leaves the sledge perpendicular to the track, as seen by someone in the frame of the track.
III) You do nothing.
Order the strategies from the best to the worst.