Teaching Minds-On Experiments on Electromagnetism in Secondary Schools

Induction
Magnet rolling down wooden plane: what direction will it roll

A strong magnet is moving on a wooden inclined plane in a Earth magnetic field. The trajectory of the magnet is not a line, only a curve.
Its velocity changes because there are interaction between the magnet and Earth magnetic field. The trajectory described by the magnet is completely different from the magnetic field lines produced by the Earth.