Animation: How a loudspeaker works. When a fluctuating electric current flows through the coil (orange), it becomes a temporary electromagnet, attracted and repelled by the permanent magnet (blue/red). As the coil moves, it moves the cone (gray) back and forth, pumping sound waves into the...
Explain how you describe the journey of blood through the heart and lungs, starting with the vena cava and finishing with the aorta. What is the difference between breathing and respiration? The movement of gas molecules into the lung upon contraction of the diaphragm and external intercostal musc...
How did the phonograph work? If you want to record sound, you speak into the tube (1). The sound energy from your voice makes a diaphragm (like a mini drumskin) vibrate, pushing a needle (2) back and forth and cutting a groove into some metal foil wrapped around a cylinder (3), ...
Large headphones are essentially just two loudspeakers mounted on a strap that clamps firmly over your head. Earbuds work the same way but, as you would expect, everything inside them (the magnet, the coil of wire, and the diaphragm cone that makes sound) is shrunk down to a much smaller...