Watch how a particle's acceleration splits into a radial part that bends the path and, when the speed itself changes, a tangential part that stretches or shrinks the velocity vector.
Mode
Parameters
Formulas
In uniform circular motion only a_r acts, so a = a_r and the particle keeps constant speed. In non-uniform circular motion a_t also acts, so the total acceleration a is always ≥ a_r — the speed is visibly stretching or shrinking as the particle goes around.