Waves Flashcards
How does light travel?
As a wave.
How can waves be measured?
By their amplitude, wavelength and frequency.
What are waves?
Waves are vibrations that transfer energy from place to place without matter.
Which waves can travel through empty space?
Microwaves, infrared rays, visible light
Transverse waves:
The oscillations are at right angles to the direction and energy transfer (has peaks and troughs)
What type of wave are light and other types of electromagnetic radiation?
Light waves.
What happens to the electromagnetic fields as waves travel?
They vibrate.
Longitudinal waves:
In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer.
What are some examples where there are longitudinal waves?
Sound waves and the waves in a stretched spring.
What are the two types of things that can be seen in a longitudinal wave?
Compressions and rarefactions
What is the amplitude of a wave?
The amplitude is the distance from the centre line to the peak or trough. (maximum disturbance from its undisturbed position.
What is the wavelength:
Wavelength is the distance between a point on one wave and the same point on the other wave (can do from peak to peak) (λ)
What is frequency:
The frequency of a wave is the number of waves that pass a certain point each second. (f)
How is wave speed measured?
In metres per second (m/s)
What is refraction?
Where waves change speed as they pass through a different substance.
What is diffraction?
Where waves meet a gap in a barrier, and spread out as they carry on through it. Smaller gap causes a bigger extent of spreading.
What does the angle of incidence equal?
The angle of reflection
The imagine in a plane mirror is:
- virtual
- Upright
- laterally inverted
What are radio waves used for?
used to transmit television and radio programmes. television uses a higher freq than radio.
A radio programme does not need to be in the view of the transmitter to receive signals, diffraction can happen.
How are radio waves reflected in the ionosphere:
The lowest frequency radio waves are reflected from the ionosphere, allowing signals to be transmitted even though they arent in the line of sight.
Which type of wave can pass through the ionosphere?
Microwaves.
Uses of microwaves:
Used to transfer signals such as mobile phone calls, microwave transmitters on buildings
What happens to the electromagnetic fields as waves travel?
They vibrate.
Longitudinal waves:
In longitudinal waves, the oscillations are along the same direction as the direction of travel and energy transfer.
