Question

Air is thrown on a sail attached to boat from a fan placed on boat . Will the boat start moving

Answer 1

So if you place your fan on your boat and turn it on so it will blow on your sail, there will be a force directed forward through the sail, and a force directed in the exact opposite direction, backward, applied on the fan. Both forces have the same intensity given the fact that they are linked. So the sum of the forces applied to the boat is a zero sum… and the boat won’t move !