Waves Flashcards
What is the amplitude of the wave
Amplitude is the maximum displacement of a point on the wave from its undisturbed position
Wavelength definition
Distance between the same point on two adjacent waves
Frequency definition
Number of complete waves passing a certain point per minute. Measured in Hz. 1Hz=1 wave per second
Period definition
The amount of time it takes for a cycle of the wave
Two types of wave
Longitudinal and transverse
Transverse wave qualities
Sideways rotation
Oscillations are perpendicular
All electromagnetic waves are transverse
A wave on a string
Longitudinal wave qualities
Parallel rotation
Oscillations are parallel to the direction of energy transfer
Sound waves in air e.g ultrasound
Shock waves e.g some seismic waves
Wave speed
Speed of which energy is being transferred(or the speed of the wave is moving at
Law of reflection
All waves can be transmitted, absorbed or reflected
What is the rule of reflected waves
Angle of incidence=angle of reflection
What is specular diffusion
Happens when a wave is reflected in a simple direction by a smooth surface. E.g when a light is reflected by a mirror and you get a nice clear reflection
What is diffuse reflectoion
When a wave is reflected by a rough surface(e.g a piece of paper)and the reflected rays are scattered in lots of different directions
Refraction explanation
Waves changing direction at a boundary. When a wave crosses a boundary between materials at an angle it changes direction-its refracted
What kind of current is used to generate radio waves in an antenna
Alternating current
Explain why microwaves are used to generate radio waves in an antenna
They pass easily through the earths watery atmosphere
Give three uses of infared radiation
Cooking food
House warming
Electrical heaters
What type of radiation is used to generate optical fibre
Visible light
Name the type of radiation used in tanning salons
Ultraviolet radiation
What does the term ionising radiation mean
Carry enough to energy to knock electrons of atoms. This causes gene mutation or cell destruction and cancer
What are the three rules for refraction in a convex lens
An incident ray parrellel to the axis refracts through the lens and passes through the principal focus on other side.
An incident ray passing through the principal focus refracts through the lens and travels parallel to the axis.
An incident ray passsing through the centre of the lens carries on in the same direction
What are the rules for refraction in a concave lens
An incident ray parrellel to the axis refracts through the lens and travels in line with the principal focus.(so it appears to have come from the principal focus)
An incident ray passing through the lens towards the principal focus refracts through the lens and travels parrrlel to the axis.
An incident ray passing through the centre of the lens carries on in the same direction
True or false? Opaque objects transmit light
False
How do colour filters work
Colour filters are used to filter out different wavelengths of light so that only certain colours(wavelengths) are transmitted- the rest are absirbed
