Waves

Energy, things like light, heat, and sound, moves in waves. You’ve probably seen waves in the ocean, or ripples when you throw a rock in a pond. Moving energy is not like the wave you do with your hand.

Energy waves have peaks and valleys, just like ocean waves. The height of each energy wave is called the amplitude, and the length between the wave peaks is called the wavelength (ha!). How often a wave goes by you in a set amount of time is called its “frequency.” When you tune your radio to 107.7, you’re tuning to its frequency 107.7 million waves per second or 107.7 MegaHertz. Hertz was a scientist who studied waves. Waves with high amplitudes (tall waves) have more energy than waves with low amplitudes (short waves). Waves with high frequencies and short wavelengths (short distances between waves) have more energy than waves with low frequencies (long distances between waves). The basic shape of energy waves is the same, but the height, speed, and distances between waves are always to measure the amount of energy in the waves. Waves have their ups and downs.

So, hang ten (toes) over your chair; surf to your TV to watch Bill Nye.

The Big Ideas

• Energy often moves in waves.
• All waves have a similar shape.

Did You Know That?

• Sound waves move through water at 1,500 meters (5,000 feet) per second?
• At 300,000 kilometers a second, light waves are the fastest thing we know of in the universe?
• Loud sounds have more energy than quiet sounds?

Books of Science!

• “Making Waves: Finding Out About Rhythmic Motion” by Bernie Zubrowski. Published by Morrow Junior Books, 1994.