Physics 1B Flashcards
What waves are in the Electromagnetic Spectrum?
Radio waves- longest wave Microwaves Infrared Visible Light Ultra Violet X-rays Gamma rays-shortest wave
What wave is used mostly for communication?
Radio waves
What wave is used for satellite communication and mobile phones?
Microwaves
Which waves can be reflected, refracted and diffracted?
All of them
What is amplitude?
The displacement (distance) between the rest position of a wave and the crest of a wave.
What is the wavelength?
The length of a full cycle of a wave (crest to crest)
What is the frequency?
The number of complete waves passing a certain point per second. Measured in hertz (Hz)- 1 Hz is 1 wave per second.
What is the difference between a transverse wave and a longitudinal wave?
- In transverse waves, the vibrations are perpendicular to the direction of energy transfer of the wave.
- In longitudinal waves, the vibrations are parallel to the direction of energy transfer of the wave.
How do you work out wave speed?
Wave speed= frequency x wavelength
(m/s) (Hz) (m)
What waves are transverse?
- Light and all other EM waves
- Ripples on water
- Waves on strings
- A slinky spring wiggled up and down
What waves are longitudinal?
- Sound waves and ultrasound
- Shock waves (seismic waves)
- A slinky spring when you push the end
Which wave can compressions and rarefactions occur?
Longitudinal waves
What is diffraction?
Waves ‘bend around’ obstacles, causing the waves to spread out.
What is refraction?
When a wave changes speed which can cause a change of direction
Why does the amount of diffraction depend on the size of the gap relative to the wavelength?
The narrower the gap or the longer the wavelength, the more the wave spreads out.
- If the gap was the same length as the wavelength then maximum diffraction will occur
- If the gap was wider than the wavelength then there will be little diffraction