law of magnetism การใช้

• This system-typical for many drop tower rides-is fail-safe, because magnets do not need powered by electricity or other sources; they work intrinsically by the laws of magnetism.
• An advantage of using magnetic field lines as a representation is that many laws of magnetism ( and electromagnetism ) can be stated completely and concisely using simple concepts such as the'number'of field lines through a surface.