Wave Motion

Waves are all around you. Ocean waves, sound waves, and light waves all carry energy from one place to another. A wave is a repeating disturbance that moves through space or matter. The interesting thing is that waves carry energy without carrying matter along with them.

Parts of a Wave

Every wave has a crest, which is the highest point, and a trough, which is the lowest point. The distance from one crest to the next is the wavelength. How tall the wave is from the middle to the crest is the amplitude. Waves with more energy have bigger amplitudes.

Types of Waves

There are two main types of waves. Transverse waves move up and down, like ripples on water. Light is a transverse wave. Longitudinal waves push and pull in the same direction they travel, like squeezing a spring. Sound is a longitudinal wave. Both types carry energy forward.

Fun Facts

• Ocean waves can travel thousands of miles across the open sea before reaching shore.
• The longest ocean waves, called tsunamis, can travel as fast as a jet airplane.
• Radio waves, microwaves, and X-rays are all different types of electromagnetic waves.

Did You Know?

When you do the wave at a sports stadium, you are actually demonstrating wave motion. Each person stands up and sits down, but the wave pattern travels around the stadium. The energy moves, but the people stay in their seats!