Unit 7: Waves

Unit 7: Waves

1. Describe the motion of different types of wave

   • Waves are repeated distrubances that move along

2. Explain the meaning of speed, frequency, wavelength and amplitude

   • speed
     • the distance travelled by a wave crest/ trough every second
   • frequency
     • the number of complete waves (or wave crests) passing a point in 1 second
   • wavelength
     • the distance from one wave crest to the next
   • amplitude
     • the height of the wave crest or depth of the wave trough from the middle

3. Use the equation 'speed = frequency * wavelength'

4. Describe the differences between transverse and longitudinal waves

   • transverse
     • waves in which the direction of vibration is perpendicular to the direction in which the wave travels
   • longitudinal
     • waves in which the direction of vibration is parallel to the direction in which the waves are travelling

5. State examples and describe applications of transverse and longitudinal waves

   • transverse
     • electromagnetic waves, waves on a rope/string
     • polaroid filters, aerials
   • longitudinal
     • sound waves, waves on a slinky

6. Describe reflection, refraction and diffraction of plane waves in a ripple tank

   • reflection
     • Plane waves reflect from a straight barrier at the same angle to the barrier as the incident waves
   • refraction
     • Refraction is the change of direction of waves when they cross a boundary due to a change in the speed of waves when they cross a boundary
   • diffraction
     • Diffraction is the spreading of waves when they pass through a gap or round an obstacle. For noticable diffraction the gap must be similar in size to the wavelength.

7. Recall that refraction is due to a change of the speed of waves when they cross a boundary

   • Refraction is due to a change of the speed of waves when they cross a boundary

8. Recall the effect of gap width on the diffraction of waves passing through a gap

   • the narrower the gap, the more the waves spread out. the wider the gap, the less the waves spread out.

9. Use wave theory to explain reflection, refraction and diffraction of waves

   • see pictures
     • reflection and refraction
     • diffraction

Images and files in the map