Bill Nye on Energy
This episode covers different forms of energy, including potential and kinetic, which you'll see again in 8th grade.
Iron filings (tiny bits of iron) can be used to see what a magnetic field looks like. Even though the magnetic energy is invisible, it causes the iron filings to line up in patterns. Click on an image to enlarge.
Watch these iron filings move as a magnet is moved around underneath them.
"Same poles repel and opposites attract!"
Bonus: Electrical generation
Just like we've seen that ELECTRICITY can create MAGNETS (electromagnets), the same thing can be done in reverse. In fact, the electricity that is powering your computer as you look at this website was produced in a power plant using giant spinning magnets. How does that work? Check out these videos:
Rather than just moving down a line, sound waves actually spread out in all directions. These three images give you a better idea of what sound waves would look like if you could see them moving through the air. Even better, check out the videos below to see sound in action!
Neat experiments with sound energy: