Final theoretical check on 2D kinematics.
I. A particle with constant speed must have zero acceleration.
II. A particle with constant velocity must have zero acceleration.
III. It is possible to have a non-zero velocity and zero acceleration.
IV. It is possible to have zero velocity and non-zero acceleration.
V. In 2D motion, the angle between velocity and acceleration vectors can be anything between 0° and 180°.
