DHS 13 Wave Motion (Notes & Tutorial)

1 Content  Progressive waves  Transverse and longitudinal waves  Polarisation  Determination of frequency and wavelength Learning Outcomes Candidates should be able to: (a) show an understanding of and use the terms displacement, amplitude, phase difference, period, frequency, wavelength and speed. (b) deduce, from the definitions of speed, frequency and wavelength, the equation v = f. (c) recall and use the equation v = f. (d) show an understanding that energy is transferred due to a progressive wave. (e) recall and use the relationship, intensity  (amplitude)2. (f) show an understanding of and apply the concept that a wave from a point source and travelling without loss of energy obeys an inverse square law to solve problems. (g) analyse and interpret graphical representations of transverse and longitudinal waves. (h) show an understanding that polarisation is a phenomenon associated with transverse waves. (i) recall and use Malus’ law (intensity α cos2 θ) to calculate the amplitude and intensity of a plane polarised electromagnetic waver after transmission through a polarising filter. (j) determine the frequency of sound using a calibrated c.r.o. (k) determine the wavelength of sound using stationary waves. H2 PHYSICS (9749) Year 6 (2025) TOPIC 13 : WAVE MOTION

2 12.1 Progressive Waves A progressive wave is a wave in which __________________ from one point to another by means of vibrations or oscillations within the waves, without transporting matter. All waves involve a disturbance from an equili brium position (i.e. an oscillation), and (for progressive waves,) the disturban ce travels from one region of space to another. However, the particles do not move along with the disturbance. 12.2 Transverse and Longitudinal Waves Transverse wave: Vibrations are ____________ to the dire ction of transfer of energy of the wave. Longitudinal wave: Vibrations are _________ to the dire ction of transfer of energy of the wave. Mechanical wave: A wave that requires ______________ for its transmission. (E.g.: sound waves and water waves) Electromagnetic wave: Wave consisting of osc illating electric and magnetic fields that are perpendicular to each other and to t he direction of transfer of energy of wave. It does not require a medium for transmission. It can travel through a vacuum at the speed of light, i.e. 3.0  108 m s−1. Progressive Waves Transverse Waves Longitudinal Waves Electromagnetic Waves Mechanical Waves Mechanical Waves

3 Electromagnetic Spectrum Refer to Annex A for more details on electromagnetic waves.

4 12.3 Characteristics of Waves Key Terms: (a) Displacement ( y): The distance i