Wave Properties Flashcards
What is a wave?
A wave is a regular vibration that carries energy.
What is a mechanical wave?
Mechanical waves are any waves that move through a medium. For example, water waves.
What is a progressive wave?
Progressive waves distribute energy from a point source to a surrounding area. They move energy in the form of vibrating particles or fields.
What are transverse waves?
Vibrations are perpendicular to the wave motion - so if the wave is travelling horizontally, the vibrations will be up and down. For example, light and water.
What are longitudinal waves?
Vibrations are parallel to the wave motion - so if the wave is travelling horizontally, the particles will be compressed closer together horizontally, or expanded horizontally as they go along (we call the expanded bit a rarefaction). The particle movement is a series of compressions and rarefactions. For example, sound and some earthquake waves.
What is displacement?
Displacement is the distance a particle moves from its central equilibrium position.
What is amplitude?
Amplitude is the maximum displacement from the central equilibrium position.
We can calculate the speed of a wave using:
v = f λ
What are standing waves?
Standing waves (also known as stationary waves) are set up as a result of the superposition of two waves with the same amplitude and frequency travelling at the same speed in opposite directions.
The waves are moving, but the position of the crests and troughs are stationary.
What is an echo?
A sound or sounds caused by the reflection of sound waves from a surface back to the listener.
What are compressions and rarefactions?
A compression is a region in a longitudinal wave where the particles are closest together. A rarefaction is a region in a longitudinal wave where the particles are furthest apart.
Difference between stationary and progressive waves
in stationary waves, there is no energy transfer along the wave, in progressive waves, there is
stationary waves have nodes and antinodes but progressive waves do not
progressive waves, all points have the same amplitude (in turn), in stationary waves, they do not
