Waves

• A wave is a disturbance that propagates through space, transferring energy with it but not matter.
• Wavefronts are the imaginary lines that join all adjacent points on the wave that are in phase.
• Vibrations or Oscillations are periodic and repetitive motions.
• A transverse wave has a direction of vibration that is perpendicular to the direction of wave travel.
• A longitudinal wave has a direction of vibration that is parallel to the direction of wave travel.
• The displacement of any point on the wave is a vector position to the point.
• The amplitude of a wave is its maximum magnitude of displacement from its rest position.
• The crests are the highest points while the troughs are the lowest points of a transverse wave.
• Being in phase describes two points on a wave that always have the same direction of motion.
• Wavelength (λ) is the shortest distance between 2 successive points.
• The period T is the time taken by each point on the wave to complete one oscillation.
• The frequency f is the number of oscillations each points completes per second.
• f= 1/T
• Wave speed v is the distance travelled by a wave per second.
• v = λ/T
• v = fλ
• From the displacement-distance graph, we can deduce the displacement of each point, amplitude, the crest and troughs, and wavelength of the wave.
• From the displacement-time graph, we are able to deduce the period and hence the frequency.