PhET: Free online physics, chemistry, biology, earth science and math simulations. The Physics Classroom. Rader's PHYSICS 4 KIDS.COM. Neodymium Magnets And Ferrite Magnets From Magnet Expert Ltd. The Physics Hypertextbook. Thunderstorms and Tornadoes - Science Activities. GCSE Physics Topics - Pass My Exams: Easy exam revision notes for GSCE Physics. Physics – teaching, learning & innovation in Malta.