How Fuel Cells Work. Polymer Electrolyte Membrane (PEM) fuel cells used in automobilesâalso called Proton Exchange Membrane fuel cellsâuse hydrogen fuel and oxygen from the air to produce electricity. The diagram and animation below show how a PEM fuel cell works.
Sound is what happens when you transmit vibrations of energy through that matter. Sound is made up of wave vibrations. When you talk aloud, the motion of your vocal cords causes the air to vibrate. Air is made up of molecules, and as those air molecules vibrate, they hit each other.
In the classical physics observed in everyday life, matter is any substance that has mass and takes up space; this includes atoms and anything made up of these, but not other energy phenomena or waves such as light or sound.[1][2] More generally, however, in (modern) physics, matter is not a fundamental concept because a universal definition of it ...