Waves Flashcards
What is a wave
Waves can be used to transfer energy
What is a transverse wave?
A wave for which the oscillations are perpendicular to the direction of energy transfer.
What is a longitudinal wave?
A wave for which the oscillations are
parallel to the direction of energy
transfer.
Give two examples of transverse waves.
- Electromagnetic waves
- Seismic s-waves
Give two examples of longitudinal waves.
- Sound waves
- Seismic p-waves
What are the two parts of a longitudinal
wave called?
Compressions and rarefactions.
What is a wave’s amplitude?
The maximum displacement of a point
on a wave from its undisturbed position.
Height of a wave measured from equilibrium position to peak
What is wavelength?
● The distance from a point on a wave to
the same position on the adjacent
wave
● Most commonly peak to peak or
trough to trough
What is the frequency of a wave?
The number of waves that pass a given
point each second.
What is meant by a frequency of 200Hz?
200 waves pass a given point each
second.
What is wave speed?
The speed at which the wave moves or
at which energy is transferred through a
medium.
What word is used to describe when a wave
bounces off a surface?
Reflection
How do sound waves travel through a
solid?
The particles in the solid vibrate and
transfer kinetic energy through the
material.
What is the frequency range of human
hearing?
20 Hz - 20kHz
What are ultrasound waves?
Waves that humans cannot hear
What is a high pitch sound?
high frequency
What is a loud sound?
Big amplitude
What is the period of a wave
Time taken for one complete wave to pass
The law of reflection states that
angle of incidence = angle of reflection
What is the normal?
normal - an imaginary line at 90° to the surface.
What is called reflection from a smooth surface?
Reflection from a smooth, flat surface is called specular reflection. This is the type of reflection that happens with a flat mirror. The image in a mirror is:
upright
virtual
How is a specular reflection?
The image in a mirror is:
upright
virtual
What is a virtual image?
In a virtual image, the rays appear to diverge from behind the mirror, so the image appears to come from behind the mirror.
What is diffuse reflection?
If a surface is rough, diffuse reflection happens. Instead of forming an image, the reflected light is scattered in all directions. This may cause a distorted image of the object, as occurs with rippling water, or no image at all. Each individual reflection still obeys the law of reflection, but the different parts of the rough surface are at different angles.