Section 2 - Waves Flashcards
What is a transverse wave?
The vibrations are perpendicular to the direction of travel
What is a longitudinal wave?
The vibrations are parallel to the direction the waves move in
What is the amplitude of a wave?
The displacement from a rest position to the crest or trough
What is the wavelength of a wave?
The length of a full cycle of a wave
What is the frequency of a wave?
The number of complete cycles of the wave passing a point per second
What is the period of a wave?
The period of a wave is the number of seconds for the wave to compete one cycle
What is infrasound?
Sound waves with frequency of less than 20Hz
What is ultrasound?
Sound waves with a frequency above 20,000Hz
What can ultrasound be used for?
Medical scans and industrial imaging
How is ultrasound used in medical scans?
Ultrasound waves will travel through the body, and some will bounce back when they come to a change in medium, like the skin of a foetus. A computer can then use these bounced back waves to create an image
How does your ear hear sound?
The sound waves cause your eardrum to vibrate. These vibrations are passed on to your ossicles, through the semicircular canals and to the cochlea. The cochlea turns these vibrations into electrical signals the brain can understand.
State two uses of infrasound
Tracking animals
Detecting erupting volcanoes, earthquakes and avalanches
What are the two main seismic waves?
P-waves and s-waves
What is the difference between p-waves and s-waves?
P-waves can pass through solids and liquids, while s-waves can only pass through solids. This means p-waves can travel through the core of the earth while s-waves can’t.
What is specular reflection?
When waves are all reflected in the same direction by a smooth surface.
