GCSE Physics Paper 2 Waves

• What is the definition of wavelength?

  Distance between the same points on consecutive waves
• What is amplitude?

  Distance from equilibrium line to maximum displacement
• What is the definition of frequency?

  Number of waves passing a point per second
• What is the definition of period?

  Time taken for a whole wave to pass a point
• What is the formula relating velocity, frequency, and wavelength?

  $𝑣 =$$𝑓λ$
• What is the formula relating period and frequency?

  $𝑇 =$$1/𝑓$
• In what units is period measured?

  Seconds
• In what units is frequency measured?

  Hertz
• How does an increase in frequency affect velocity, assuming wavelength is constant?

  Velocity increases
• How does an increase in wavelength affect velocity, assuming frequency is constant?

  Velocity increases
• How are period and frequency related?

  Inversely proportional
• How does a smaller period affect frequency and velocity?

  Higher frequency, greater velocity
• Which parts do transverse waves have?

  Peaks and troughs
• How are the vibrations oriented relative to the direction of travel in a transverse wave?

  At right angles
• What are the parts of a longitudinal wave?

  Compressions and rarefactions
• How are the vibrations oriented relative to the direction of travel in a longitudinal wave?

  In the same direction
• What actually moves when a wave travels through a medium?

  The wave
• What equation is used to calculate speed, given distance and time?

  speed = distance/time
• How can you measure the speed of sound in air using an echo?

  Record the time for the echo
• How can you measure the speed of sound using two microphones and a datalogger?

  Record the time difference between the sound
• How can you measure the speed of ripples on a water surface using a stroboscope?

  Measure distance between 'fixed' ripples
• What are the units for wave speed, frequency, and wavelength in the equation $𝑣 =$$𝑓λ$?


  m/s, Hz, and m
• How can you measure the speed of ripples on water by moving a pencil along paper?

  Measure time taken to draw the line
• What three things can happen to waves at the boundary between two materials?

  Reflected, absorbed, or transmitted
• What happens when a wave reflects off a flat surface?

  The wave reflects
• How does the smoothness of a surface affect the strength of a reflected wave?

  Smoother surface, stronger reflection
• Why do rough surfaces appear matt?

  They scatter light in all directions
• What is the relationship between the angle of incidence and the angle of reflection?

  They are equal
• Under what conditions will light reflect off an object?

  Object is opaque and light is not absorbed
• How do electrons contribute to reflection?

  Absorb light, then reemit it
• What happens when waves pass through a transparent material?

  The waves are transmitted
• How does transparency affect the amount of light passing through a material?

  More transparent, more light passes through
• What can happen to waves when they are transmitted?

  They can refract
• What happens during absorption when the frequency of light matches the energy levels of electrons?

  Light is absorbed by the electrons
• What happens to the energy of absorbed light over time?

  Reemitted as heat
• What happens to a particular frequency when it is absorbed?

  It is not reemitted
• If a material appears green, what has happened to the other frequencies of visible light?

  They have been absorbed
• If a material appears green, what has happened to the green light?

  It has been reflected
• What effect can sound waves have when travelling through solids?

  Cause vibrations
• What part of the ear collects sound?

  Outer ear