Waves

• What is amplitude?

  The maximum displacement of a wave from its undisturbed (equilibrium) position
• Where is the angle of incidence found?

  Between the incident ray and normal
• Where is the angle of reflection found?

  Between the reflected ray and normal
• An object will appear black if it absorbs all wavelengths of light
• What does it mean if an object is at a constant temperature?

  It is absorbing radiation at the same rate that it is emitting it
• What are the two types of waves?

  Transverse and Longitudinal
• What is a transverse wave?

  Where the oscillations are perpendicular to the direction of energy transfer/wave travel
• What is a longitudinal wave?

  Where the oscillations are parallel to the direction of energy transfer/wave travel
• Give two examples of transverse waves

  i. Electromagnetic waves

  ii. Seismic S-waves
• Give two examples of longitudinal waves

  i. Sound waves

  ii. Seismic P-waves
• What are the two parts of a longitudinal wave?

  Compressions and rarefactions
• What is wavelength?


  The distance from a point on a wave to the same position on the adjacent wave
• Which two parts of a wave are most commonly used to work out wavelength?

  Peak or trough
• What is the frequency of a wave?

  The number of wave passing a point each second
• The unit used for frequency is hertz (Hz)
• What does it mean by a frequency of 200Hz?


  200 waves pass a given point each second
• What is wave speed?

  The speed that a wave travels at through a medium
• Waves transfer energy
• What is the equation for wave speed?


  v = λf

  wave speed = wavelength × frequency
• Wave speed is measured in metres per second (m/s)
• Frequency is measured in hertz (Hz)
• Wavelength (λ) is measured in metres (m)
• The speed of sound in air is 330m/s
• What is the equation for a period?

  T = 1/f

  period = 1/frequency
• Reflection describes when a wave bounces off a surface
• How do sound waves travel through a solid?

  The particles in the solid vibrate and transfer kinetic energy through the material
• What is frequency range of human hearing?

  20Hz - 20kHz
• What are ultrasound waves?

  Sound waves that have a frequency above the upper limit of human hearing (20kHz)
• Give an example use for ultrasound wave

  Medical or industrial imaging
• What natural event causes seismic waves?

  Earthquakes
• What type of seismic waves are produced by earthquakes?

  Both P-waves and S-waves
• What is the difference between the mediums P-waves and S-waves can travel through?

  P-waves can go through solids as well as liquids. S-waves can only travel through solids
• What technique is used to detect objects in deep water and measure water depth?

  Echo sounding
• How does echo sounding work?

  High frequency sound waves are emitted. The time between sound being transmitted and detected + the speed of sound in water can be used to calculate distance of the object.
• Electromagnetic waves form a continuous spectrum.
• i. Order types of electromagnetic radiation from lowest to highest frequency.

  ii. The order is also same for their...

  i. Radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays

  ii. wavelength from longest to shortest
• EM waves with higher frequencies have more energy than those with lower frequencies.
• How do the speeds of EM radiation differ in a vacuum or in air?


  They don't differ, they all travel at the same speed
• There are 7 types of electromagnetic waves
• What is refraction?

  Change of direction in a wave when crossing a boundary between materials