That one worked because it was just an inneficient way of pointing the fan backwards, the center of mass, as the average of the position of all the mass doesn’t move from inside forces, just outside ones, so for the car to move the mass of the magnet and arm would meet to move in relation to the car, because they can’t, the car doesn’t move too.
Wich is basically just a long way of saying “Newton laws”.
Mythbusters did a similar one using a fan and a sailboat. The boat moved. Backwards.
That one worked because it was just an inneficient way of pointing the fan backwards, the center of mass, as the average of the position of all the mass doesn’t move from inside forces, just outside ones, so for the car to move the mass of the magnet and arm would meet to move in relation to the car, because they can’t, the car doesn’t move too.
Wich is basically just a long way of saying “Newton laws”.