Dropper poper

Dropper-popper turns the elastic energy into kinetic energy. If it falls in its 'turned inside out' shape, the kinetic energy is released at the moment of collision and it sums up with kinetic energy of the fall - as a result the ball rebounds higher than the height from which it was dropped.

Instead of dropping the ball from a particular height we can turn it inside out, place it on a table and after 'returning to its previous shape' the ball will rebound at a certain height by itself.

In this way we can assess easily how much elastic energy it can store. For example, if such a semi-sphere ball weighs ca. 18 grams, and after rebounding it reaches the height of 1.3 metres, the elastic energy transformed into kinetic energy and later into potential energy mgh is 0.23 J and its initial velocity at launch is ca. 5 m/ s. The above is the case, provided that energy conversion process takes place without dissipation, i.e. energy loss resulting from radiating heat or overcoming the resistance of movement.