Adevice that changes electrical energy into mechanical energy?

What are two examples of conduction that we use everyday

The small molecule cyclic amp (camp) takes about 0.2 second to diffuse 10 μm, on average, in a cell. suppose that camp is produced near the plasma membrane on one end of the cell; how long will it take for this camp to diffuse through the cytosol and reach the opposite end of a very large cell, on average? assume that the cell is 200 μm in diameter.

Which of the following is an eon in the time scale? phanerozoic proterozoic archean all of the above