That's Entertainment - Waves Section Flashcards
Do particles or energy move along a wave?
Wave energy does, particles do not.
What is a crest of the wave?
Top of wave
What is the trough?
Bottom of wave
What is an amplitude?
The heigh of the crest or trough from it’s rest position
What is a wavelenghth?
The length of one wave from crest to crest.
What is frequency?
The number of waves passing a point in one second. Measure in hertz (Hz)
What is speed?
The distance a wave travels in a certain time (m/s)
What do light waves travel as?
Transverse waves
What do sound waves travel as?
Longitudinal waves.
What is absorption?
Absorption happens with light waves.
• When white light falls on a black object it is absorbed eg. Seeing a coloured object
• Opaque objects do not allow light to penetrate
• Transparent objects allow light to penetrate
• Translucent objects allow some light to penetrate
How do we see colours?
Visible light is made up of seven colours, these rays hit an object. All the colours are absorbed except the colour of the object which is reflected into your eyes.
What is reflection?
Light waves bouncing off objects
• Angle of incidence = angle of reflection
• Eg. Reflection off a mirror
What is refraction?
Bending of light through different matter
• Bend more in a solid as the particles are closer
Together, compared to travelling through a gas where the particles are further apart this causes the light to change its speed
• Eg. Refraction while fishing in water
What happens to energy in a sound wave?
When particles begins to vibrate they start to ‘bump’ into each other
What happens to sound waves in solids?
The particles vibrate faster as the particles are closer together or more dense so the transfer of energy is much quicker. The sound will travel faster through a solid object.
What happens to sound waves in gas?
The particles are less dense or further apart the energy transferred from on particle to another is much slower therefore sound travels through a gas much slower. This is opposite to travelling through solids.
Where do sound waves travel slower? Gases, liquids, or solids?
Gases
What is the electromagnetic spectrum
The electromagnetic spectrum includes Electromagnetic radiation (EMR), a form of energy that moves as waves as it travels through space.
What are gamma rays used for?
Treat cancer, radioactive source
What are x-rays used for
X-ray photographs to examine bones, metal objects for cracks, luggage at airports
What are ultra violet rays used in?
Fluorescent tubes
What is visible light used in?
Seeing and lasers.
What is infrared rays used for?
Remote controls in TV’s, cameras, satellites, telescopes.
OPTICAL FIBRE AND COMMUNICATIOn
What are microwaves used for?
Cooking in microwave ovens, radar
What are radio waves used for?
AM, FM radio, television signal
Are waves with the highest frequency have the shortest or longest wavelength?
The shortest. Waves with low frequencies such as radio waves have long wavelengths in order to produce signals to long distances.
