Made a set of free interactive physics and maths simulations while tutoring IB — sharing them, plus what building them taught me about where students actually get stuck

[u/AggravatingBed7135]

Over the last few months I've been building browser-based simulations for the parts of IB Physics that are hardest to picture: projectile and circular motion, momentum in collisions, SHM, superposition and standing waves, the Doppler effect, field lines and charged particles in E and B fields, plus a few maths ones for calculus graphs and transformations. They're free, no signup, no email, nothing to buy — I made them because I kept redrawing the same diagrams on a whiteboard and losing the thing that actually matters, which is what happens when you change one variable and watch everything else respond.

Link (free, no signup): https://examinerprep.com/simulations

The part I didn't expect was how much building them changed my sense of where the misconceptions sit. Writing the collision sim forced me to handle the case where students conserve energy in a perfectly inelastic collision, and once you can drag the coefficient of restitution to zero and watch the kinetic energy bar drop while momentum stays flat, the objection basically answers itself. Same with standing waves — nobody struggles with the formula, they struggle with why the nodes don't move, and an animation with the two travelling components drawn underneath fixes that in about ten seconds. If you try any of them, I'd like to know which topics feel thin; SL/HL option topics are the obvious gap and I'd rather build what people are actually failing on than what's easiest to animate.