Waves Flashcards
What are the two types of waves?
Transverse and longitudinal.
What do waves do?
Transfer energy from one place to another.
What do the particles that make up a wave do?
Oscillate (vibrate) around a fixed point, to pass energy onto the next particles.
What are the oscillations like in a transverse wave?
Perpendicular to the direction of energy transfer.
What are the oscillations like in a longitudinal wave?
Parallel to the direction of energy transfer.
What is the frequency of a wave?
The number of waves passing a fixed point per second (Hz).
What is the amplitude of a wave?
The maximum displacement that any particle achieves from its undisturbed position (m).
What is wavelength?
The distance from one point on a wave to the equivalent point on the next wave (m).
What is the period of a wave?
The time taken for one complete oscillation (s).
With water waves, what are some useful observations?
Amplitude is seen as the wave height.
The period is the time taken for one complete wave to pass a fixed point.
What can amplitude show?
It indicates the amount of energy a wave is carrying.
What is the speed of a wave?
The speed at which energy is transferred/the wave moves.
What type of waves are electromagnetic waves?
Transverse.
What does the wavelength of an electromagnetic wave affect?
How it is absorbed, transmitted, reflected, or refracted.
What are all the types of electromagnetic waves in order from low frequency?
Radio waves. Microwaves. Infrared rays. Visible light. Ultraviolet rays. X-rays. Gamma rays.
How might a wave be refracted?
When is passes from one medium into another.
What does the direction of refraction depend on?
The angle at which the wave hits the boundary.
The materials involved.
What is the refractive index of a material?
The way in which the material affects refraction.
How do light rays react when they pass from a material with a low refractive index into a material with a high refractive index?
It bends towards the normal.
How do light rays react when they pass from a material with.a high refractive index into a material with a low refractive index?
It bends away from the normal.
What is refraction the result of?
The difference in wave speed in the different media.
What are ray diagrams used to show?
What happens when waves are refracted.
What can radio waves be used for?
Television, radio, bluetooth.
What can microwaves be used for?
Satellite communications, cooking food.
What can infrared waves be used for?
Electrical heatings, cooking food, infrared cameras.
What can visible light be used for?
Fibre optic communications.
What can ultraviolet waves be used for?
Energy efficient light bulbs, security marking, sunbeds.
What can X-rays be used for?
Medical imaging and treatments.
What can gamma rays be used for?
Sterilising food, treatment of tumours.
What can radio waves be caused by?
Oscillations in electrical circuits (like an alternating current).
What happens when radio waves are absorbed by a conductor?
They may create an alternating current with the same frequency of the radio wave.
What changes in atoms, and the nuclei of atoms, can generate waves?
Electrons moving between energy levels as a result of heat and electrical excitation.
Changes in the nucleus (such as an unstable one emitting gamma rays).
What risks do ultraviolet waves hold?
Causes skin to age prematurely.
Increases the risk of cancer.
What risks does ionising radiation cause?
Such as X-rays and gamma rays, they can damage cells by ionising atoms and cause gene mutations and cancer/
