Describe how energy can be converted from one form to another in a wind-up toy.

The idea of a mechanical device, like a wind up toy, is to take take advantage of the laws of thermodynamics in order to perform some kind of work.

In the case of a wind up toy, mechanical energy (winding the handle) is stored as potential energy in an internal spring. This creates a state of 'low entropy' in the toy since work was done to concentrate energy in the spring.

The natural tendency of the spring is to unwind and distribute it's energy in a more disordered fashion, thereby increasing entropy and following the laws of thermodynamics.

The mechanism inside the toy is engineered to focus the flow of energy being delivered by the spring into a specific mechanical motion (Kinetic Energy), then sound (air pressure) and finally heat (thermal energy).