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 actually an energy wave of molecules that create a vibration. Sound can travel through and bend around many objects, including water. Check out how sound works: 1  When an object moves it creates a vibration. 2  Vibrations move air particles around. 3  These moving particles are constantly bumping into each other. 4  Our ears can pick up these particle-vibrations as sound. 5  Fast moving particles create a high sound, while slow ones are low-sounding.