system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do electric tooth brushes vibrate slowly when on low power instead of running normally then suddenly shutting off?
gpt
They use a simple electromagnetic motor, which means that when the electricity goes through it then it pushes a magnet attached to the part of your brush that’s vibrating. Now the battery provides the electricity, but as the chemical reaction that is happening inside the battery starts slowing down it doesn’t stop all at once, rather it slowly peters out, like a fire does. So the motor still gets pushed, but not as fast. This keeps going until the battery just isn’t pushing the electricity enough to start the motor at all and your toothbrush is dead.