Waves Flashcards
Give 3 properties of EM waves.
- They are able to travel through vacuums (empty space)
- They transfer energy, not matter
- They are all transverse
At what speed do EM waves travel on average?
300,000,000 m/s
What do EM waves NOT transfer?
Matter.
Name 7 types of EM waves.
Radio, Microwave, Infrared, Visible, Ultraviolet, X-ray, Gamma
State the formula for frequency.
Frequency = number of waves passing through a fixed point ÷ time
Give the formula for wave speed.
Wave speed = frequency × wavelength
Define amplitude.
The maximum displacement of a wave from its equilibrium position.
What is a Period (T)?
The time taken for one full wavelength to pass through a fixed point.
What is a Period measured in?
Seconds.
How are waves created?
Waves occur when an object vibrates and disturbs substances in its surroundings. To create a wave, you must disturb a medium, e.g. water.
What are the two different kinds of wave?
Transverse and longitudinal.
What are the differences between transverse waves and longitudinal waves?
Transverse waves move at right angles to the direction of the wave, longitudinal waves move in parallel to the direction.
Draw a diagram of a transverse wave.
Must include Amplitude, Movement of particles, Trough, Crest, Wavelength, Direction of Energy Transfer, and Equilibrium position.
Draw a diagram of a longitudinal wave.
Must include rarefaction, compression, sideways vibration creating the wave, and direction of energy transfer.
Define a wave.
Phenoma that transfer energy without transferring matter.
Define wavelength.
The distance between two identical points on a wave. It is measured in metres.
What equipment is needed to determine wave speed in a ripple tank? Draw a sketch.
Should have white card, lamp, motor, power supply, metre ruler and a wooden rod.
What are the independent variables of the measuring wave speed PAG?
frequency of the waves
Wavelength
How do lenses form images?
By refracting the light that passes through them.
What is the principal focus?
Where all the lines on a ray diagram meet.
Define the focal length.
The distance between the centre of the lens and the principal focus.
