Waves Flashcards
(31 cards)
Wavelength definition
Distance between the same points on two consecutive waves. Can be from trough to trough or crest to crest.
Amplitude definition
Maximum displacement from rest position to either the crest or trough.
Frequency definition
Number of complete waves passing a certain point per second.
Period definition
The number of seconds it takes for one full cycle.
What are the properties of a transverse wave?
Vibrations travelling perpendicular to the direction the wave travels and the energy transferred. The vibrations go up an down.
What are the properties of a longitudinal wave?
Vibrations travelling parallel to the direction the wave travels and the energy transferred. The vibration push and there are rarefactions and compressions.
Ultrasound Definition
A sound wave with frequencies higher that 20,000Hz
Infrasound Definition
A sound wave with frequencies lower than 20Hz
What happens when a wave is absorbed?
The wave transfers energy to the material’s energy stores
What happens when a wave is reflected?
When the waves bounces of a boundary of two different medias. The angle of incidence is equal to the angle of reflection.
What does it mean by incident angle?
The angle of the entering ray
What does it mean by reflected angle?
The angle of the exiting ray
What happens when a wave is refracted?
When the wave changes direction and speed when entering different densities.
What happens to the speed of the wave when bending towards the normal?
It slows down.
What happens to the speed of the wave when bending away the normal?
It speeds up.
What happens to the speed of the wave when bending away the normal?
It speeds up.
How does the human ear detect sound?
- The pinna collects and funnels sound into the ear canal.
- The sound waves travels through the ear canal and causes the ear drum to vibrate.
- Three small bones transmit these vibrations to the cochlea.
- This produces electrical signals which pass through the auditory nerve to the brain
- the brain interprets the sound
What happens to ultrasound waves at a boundary?
They partially reflect at boundaries. This can be used to detect how far away something is.
How can ultrasound be used for medical scans?
- The waves pass through the body but when it hits a boundary some of the wave is reflected back and detected.
- these echoes are processed by a computer and produces a video image of the foetus
What is the angle of incidence?
the angle between the incoming light ray and the line of normal
What is the angle of the refraction?
the angle between the normal and the refracted light ray
What are sound waves?
- Caused by vibrating objects
- longitudinal
What type of waves do earthquakes produce?
seismic
What are the types of seismic waves?
p and s waves
