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.
Sound is mechanical energy, and anything that exhibits movement can make sound. But the sound has to have something to travel in. A gas or a liquid or a solid is a medium, and â¦ the sound will travel in them (or will be conducted through them).ound is mechanical energy, and anything that exhibits movement can make sound. But the sound has to have something to travel in. A gas or a liquid or a solid is a medium, and â¦ the sound will travel in them (or will be conducted through them).