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.
Matter is the stuff in the universe, and sound is a vibration of energy moving through that stuff. When we talk or make a sound, we cause the air molecules to vibrate and hit each other. These vibrations eventually reach our ears and vibrate our ear drums, allowing us to hear a sound and make sense of it in our brains.