Experiment: I construct a mini car by using a fresh AA battery and place a few magnets on both ends. I place the magnets with the same pole facing out from the magnet, and the magnets are attracted and stick to the steel parts of the battery.
Observation (EXPECTED): When this stack of batteries and a magnet is placed on a thin layer of conductive aluminum foil, an electric current runs through the foil. In the presence of the magnetic field, this current makes a force that propels the car.
Explanation: This setup provides the two main ingredients of an electric motor: A flow of electric current and a strong magnetic field. We get electrical current because there’s an electrical contact between the battery, through the magnets, through the foil, through the magnets on the other end, and back into the battery. The magnets are arranged with the same poles facing out. This provides a good magnetic field that’s in a uniform direction across the length of the foil (under the battery). Thus, the current is flowing through a place where there is a strong magnetic field.
Why my experiment fails? It could be due to 2 reasons: 1. the AA battery is not strong enough, 2. the magnets are not exactly centered on one end (like in the video).