P6 - Waves Flashcards
What is amplitude?
The maximum displacement of a point on a wave, away from it’s undisturbed position.
What is frequency?
The number of waves passing a particular point per second.
What is wave length?
The distance from one point on one wave to the equivalent point on an adjacent wave.
What is wave length measured in?
Lambda
What is a period?
The time it takes for a wave to complete a full cycle.
What is amplitude measured in?
Amps (A)
What is frequency measured in?
Hertz (Hz)
What are the 2 types of waves?
Longitudinal and transverse.
What is a longitudinal wave?
When the oscillations are parallel to the direction of energy transfer.
What is a transverse wave?
The oscillations are perpendicular to the direction of energy transfer.
What is an oscillation?
A vibration about a rest posistion.
What is Echo sounding?
Used to detect objects in deep water and detect water depth.
What is the limit of human hearing?
20,000 Hz (anything above this is called an ultrasound)
How do you measure wave length?
Place a metre ruler perpendicular to the waves shown on the card.
Measure across as many waves as you can.
Divide that length by the total number of waves.
How do you measure wave frequency?
Count the number of waves passing a chosen point over a given time.
Divide the number of counted waves by the given time period.
What is the normal?
An imaginary line drawn perpendicular to the plane.
What is the angle of incidence?
The angle between the incident (incoming ray) and the normal.
What is the angle of reflection?
The angle between the reflected ray (outgoing ray) and the normal.
What is a rule linking the angle of incidence and the angle of reflection?
Angle of incidence = angle of reflection
What is a specular reflection?
When a reflection surface is smooth so, waves are reflected in a single direction.
What is diffuse reflection?
When a reflection surface is rough, scattering occurs, meaning waves are reflected in different directions.
What is refraction?
The change of direction caused by waves changing speeds as they enter a different material.
What happens when a ray enters a more dense material?
It slows and moves towards the normal.
What happens when a ray enters a less dense material?
It speeds up and moves away from the normal.