# Accumulating and changes in direction

Physics Narrative for 14-16

## Predicting circular and parabolic paths

Velocity vectors predict where something will end up after a short interval of time. Following a sequence of such predictions maps out a route that you'd expect the object to follow.

Two interesting patterns that arise are where the vectors change in a systematic way with time. Changes in the velocity vector over time are, of course, the results of an acceleration.

There could be any number of patterns of change in the velocity vectors.

These two are of particular interest because of the resulting patterns of motion.

- The change in the velocity is at right angles to the existing vector.
- The change in velocity vector is always in one direction, and is a result of uniform acceleration.

These produce circles and parabolas, both of which are rather common motions.