Okay. Maybe even dumb it down a little more? Just in case someone out there still doesn’t get it. Not me, I get it. Just someone else might not, and what about them you know?!
I think this is the best answer. Just because magnetism is not visible doesn't make it magic. The source of the forces doesn't change where those forces go. A lot of these perpetual motion machines can be simplified to a situation that makes intuitive sense.
So, hypothetically, what if we replaced the magnet on the stick with a stronger magnet? (I'm sure this wouldn't work, I just don't know why it wouldn't work lol)
It doesn't work because, while the front magnet is pulling the car magnet forward, the car magnet is also pulling the front magnet backwards and the front magnet is also attached to the car, so it cancels out.
In simplest terms, the two magnets are trying to pull toward each other equally. But when you glue them on the board, that glue holds the magnets apart, and "pushes" them the same amount that the magnets "pull" towards each other, hence no movement.
There would only be a movement if one side was pulling more than the other. The hand is providing that imbalance at first which moved the car.
Magnet want to pull and stick to each other of the different pole. When it glued to the car, the one on the cardboard will want to move toward the car and the one on the front hood will want to move toward the cardboard. The force cancel each other out so no movement will happen.
In this situation the magnets act much like a spring, so imagine changing the magnets on the stick and the car for a simple spring. That is much more easier to visualize.
Ok when not glued: both magnets get pulled to each other. The hand has to use some force in order to stay in place, so the car moves.
When glued: both magnets still get pulled to each other, but now the force is cancelled out since the force that would pull it forward also has to be used to hold the other in place.
Not quite the same as the two magnets. If you have a big fan and a square sail, you're moving air, which has mass and is not attached to the boat. That alone will cause a force that moves the boat backwards. The moving air that hits the sail will not fully cancel that force due to frictional losses and air spillage from the edges.
Racing yachts are a different story. They have rigid sails that are shaped like airfoils. Blowing across an airfoil causes lift. So a big fan blowing perpendicular to the axis of the boat across such a sail would move the boat forward. But it's much more efficient for the fan to blow backwards without the sail, hence airboats and hovercraft.
No one is commenting about the magnet on the back of the car and possibly a magnet in the person's hand causing the rear magnet to repel against the hand magnet?