Wave Energy and Types of Waves

Study Notes

Nothing stays still in nature. From tiny subatomic particles to the whole planet, energy travels in vibrations. These vibrations are called waves.
Waves are the most familiar, such as ocean waves, but also earthquakes, and sound.
Light waves are transverse waves. They vibrate up and down at right angles to the direction the wave is traveling.
Sound waves are longitudinal waves. They travel through air, water or rocks. Instead of vibrating up and down, the particles squeeze together and then spread out in the same direction as the wave motion.

There are two types of waves: transverse and longitudinal.
Transverse waves vibrate perpendicular to the direction of wave motion (e.g., light waves).
Longitudinal waves vibrate parallel to the direction of wave motion (e.g., sound waves).

Every wave has two basic measurements.
Wavelength: The distance from one crest to the next.
Frequency: The number of waves that pass a point in one second. This is measured in Hertz (Hz).

On a windy day, there are lots of waves on the ocean. It can be hard to see single waves moving across the water.
Interference occurs when two waves meet and combine.
If the crests of two waves match up, they merge into a single wave that is twice as high as the originals.
If the crest of one wave meets the trough of another, then the two waves would cancel.

The simplest wave behavior is reflection. All waves reflect when they meet a stable surface.
When a light wave hits a mirror, the direction of the wave is changed according to the angle at which it hits the mirror.

Have you ever wondered why you can hear noises coming from around corners?
Diffraction is a process that occurs when light waves or sound waves pass through a gap.
The smaller the gap, the more the waves will spread and they travel with the same frequency and wavelength.

In 1935, American scientist Charles Richter made a way to measure earthquakes.
He called it the Richter scale.
The scale measures the strength of earthquakes.
Earthquakes are rated 0 on the Richter scale.
Each number on the Richter scale is 10 times more powerful than the number before it.