Waves

5/22/2012

Waves

Waves travel and transfer energy in an oscillating fashion (they wiggle).

The amplitude, y, of a wavedescribes its height fromzero to a crest.

The wavelength, λ, of a wave is the distance between crests.

Waves & Energy

If both waves travel at the same speed, which one would have more complete wave cycles passing a point in a given time interval?

Since waves transfer energy, which one has more energy?

Higher frequencies have higher energy & lower wavelength.

shorter

shorter

Waves & Energy

Longitudinal Waves

Sound waves are called longitudinal, which means that the vibration is back and forth in the same direction as the direction of travel.

In our slinky demo, longitudinal waves (or compression waves) moved along the slinky, not up & down.

Sound is a longitudinal wave, meaning that the vibrations move the same direction the wave is traveling in

Transverse vs. Longitudinal Waves

Transverse Waves

Light waves are called transverse, which means that the vibration is perpendicular to the direction the waves is traveling. So if a wave is moving from left to right, the vibration is up and down.

In our slinky demo, transverse waves were when the slinky moved up and down.

Transverse waves (water waves, light waves) move perpendicular (at a 90o angle) to the direction of the wave and the direction its energy is traveling

Transverse vs. Longitudinal Waves

Example of what a speaker does to air molecules to produce sound

A longitudinal wave!