Slinky Dog Dash

Behind the train, you can see some of the white fins that are part of the Linear Synchronous Motors (LSM) used to launch the train.  A massive amount of electricity passing through these fins creates a magnetic field that interacts with permanent magnets mounted underneath the train.  By controlling the magnitude and direction of current flow, the fins either attract or repel the magnets on the train.  A collection of proximity sensors in the track can sense the speed and location of the train, and computers vary the electricity sent to the LSM fins in order to impart the correct acceleration to the train.