CollSim

CollSim is a 2D collision visualisation for exploring how objects interact in mechanics. It is intended as a classroom-facing tool for linking motion, momentum, energy, and model assumptions.

Physics concept

Two-dimensional collisions, conservation of momentum, kinetic energy, elastic and inelastic interactions, and vector decomposition.

Learner difficulty

Students often reason about collisions as isolated before/after events and lose sight of the vector nature of momentum. They may also conflate energy conservation with momentum conservation.

Didactic idea

The app is designed to make the geometry of a collision visible: learners can compare initial and final velocity vectors, discuss what is conserved, and test how changing mass or velocity affects the outcome.

Evidence/status

Experimental teaching tool. It is suitable for demonstrations, short prediction tasks, and exploratory student work where the emphasis is on qualitative reasoning before formal calculation.