A series of demonstration experiments devoted to the relativity of translational motion in inertial and non-inertial reference frames is proposed. We recommend a simple algorithm for the formation of the ability to transform coordinates, speeds and accelerations during the transition from one reference system to another system moving translationally relative to the first one. Stroboscopic photographs of an experiment are given. In this experiment, a ball flies after a shot from a platform moving along a straight line uniformly or having a constant acceleration.