Waves Flashcards
Are sound waves longitudinal or transverse waves?
Longitudinal
What is frequency?
The number of waves passing a point each second
What is the equation for time period?
Time period = 1/frequency
In a vaccume how do the speeds of electromagnetic waves compare to each other?
Same speed
What is the order of electromagnetic spectrum?
- Radio wave
- Microwave
- infrared
- visible light
- ultraviolet
- X-rays
- gamma rays
What is the water tank experiment an example of?
Transverse waves
What is amplitude?
The maximum displacement of a wave
What is the equation for wavelength?
Wavelength = speed / frequency
What is a transverse wave?
Direction of a vibration and the flow of energy are at right angles
What is a longditudional wave?
Direction of wave and flow of energy are paralell
What is the ripple tank experiment for wavelength ?
- have water waves and strobe on at same frequency (which allows the waves to look stationary)
- measure the first to last wavefront with a ruler and divide by amount of waves
Wavelength = length of ripple tank / number of waves
What is the law of reflection?
That the angle of incidence = angle of reflection
What is the ripple tank experiment for the speed of a wave?
- measure whole length of ripple tank
- pick one wave and start stopwatch from it being formed to reaching the other end of ripple tank
- repeat to remove anomalies
- calculate a mean
- calculate velocity by equation:
Velocity = frequency x wavelength
What are all waves made by?
Vibrations / oscillations
What is a rarfraction?
Light passing through something transparent / translucent
What does a shorter wavelength in electromagnetic wave mean it can do easier?
Pass through skin tissue
What are radio waves produced by?
Oscillations in electrical circuits
What do radio waves create when they are absorbed?
An alternating current with the same frequency as the radio itself
How are gamma rays formed?
Radioactive decay (changes inside the nucleus of an atom)
What is a ‘radiation dose’?
A measure of the risk of harm resulted from exposure to radiation
What can UV rays cause?
Skin cancer and premature skin aging
What type of radiation is X-rays and Gamma rays and what does it cause?
- ionising radiation
- mutation of genes and cancer
What are radio waves used for and why?
Television and radio
They can travel long distances before being absorbed
What are microwaves used for and why?
- satellite communications, cooking food
- microwaves can pass through the earths atmosphere without being reflected or refracted
