one example of conversation of mechanical energy to electrical energy is
Mechanical energy Many devices are used to convert mechanical energy to or from other forms of energy, e.g. an electric motor converts electrical energy to mechanical energy, an electric generator converts mechanical energy into electrical energy and a steam engine converts heat energy to mechanical energy.
Speed of electricity The word electricity refers generally to the movement of electrons (or other charge carriers) through a conductor in the presence of potential and an electric field. The speed of this flow has multiple meanings. In everyday electrical and electronic devices, the signals or energy travel as electromagnetic waves typically on the order of 50%â€“99% of the speed of light, while the electrons themselves move (drift) much more slowly.