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148 Pages

 Specification Reference Summary of Specification contents. Learning Outcomes P1.5.2 Reflection P1 Lesson 27&28 Reflection a The ‘normal’ is a construction line perpendicular to the reflecting surface at the point of incidence. Draw diagrams showing rays of light being reflected from a plane mirror, labelling incident and reflected rays, angles of incidence and reflection, and the normal. b The angle of incidence is equal to the angle of reflection. c The image produced in a plane mirror is virtual, upright and laterally inverted. Understand how an image is formed by a plane mirror, and why it is virtual. P1.5.1 General properties of waves P1 Lesson 29&30 Basic Properties of Waves a Waves transfer energy. Understand that in a transverse wave the oscillations are perpendicular to the direction of energy transfer. b Waves may be either transverse or longitudinal. Understand that in a longitudinal wave the oscillations are parallel to the direction of energy transfer. c Electromagnetic waves are transverse, sound waves are longitudinal and mechanical waves may be either transverse or longitudinal. Recall examples of transverse and longitudinal waves d All types of electromagnetic waves travel at the same speed through a vacuum (space). Describe similarites between electromagnetic wave eg, speed, travel through a vacuum, they are transverse. f Longitudinal waves show areas of compression and rarefaction. Explain the terms ‘compression’ and ‘rarefaction’ and how they are formed. I The terms ‘frequency’, ‘wavelength’ and ‘amplitude’. Explain the terms ‘frequency’, ‘wavelength’ and ‘amplitude’ and be able to annotate a diagram to show these terms. P1 Lesson 31&2 Reflection, Refraction and Diffraction g Waves can be reflected, refracted and diffracted. Describe the circumstances where a wave is reflected, refracted or diffracted. Be able to complete wavefront diagrams for reflection, refraction and diffraction. h Waves undergo a change of direction when they are refracted at an interface. Know that waves are not refracted if travelling along the normal. P1 Lesson 33 The Wave Equation I The terms frequency, wavelength and amplitude. Be able to use the equation, knowing that v is speed in metres per second (m/s) f is frequency in hertz (Hz) and λ is wavelength in metres (m). j All waves obey the wave equation: v = f × λ P1 Lesson 34&35 Uses of Radio waves, Microwaves, Infra Red and Visible light for communication. k Radio waves, microwaves, infrared and visible light can be used for communication. Describe situations in which waves are typically used for communication, eg: radio waves – TV and radio (including diffraction effects), microwaves – mobile phones and satellite television, infrared – remote controls, visible light – photography. P1.5.3 Sound P1 Lesson 36&37 Sound a Sound waves are longitudinal waves and cause vibrations in a medium, which are detected as sound. Know how sound waves are produced. b The pitch of a sound is determined by its frequency and loudness by its amplitude. Understand the relationship between the pitch of a sound and the frequency of the sound wave. c Echoes are reflections of sounds. Understand how echoes are formed. P1.5.4 Red-shift P1 Lesson 38 Evidence for the big bang a If a wave source is moving relative to an observer there will be a change in the observed wavelength and frequency. This is known as the Doppler effect. Be able to explain the Doppler effect. Know that when the source moves away from the observer, the observed wavelength increases and the frequency decreases; when the source moves towards the observer, the observed wavelength decreases and the frequency increases. b There is an observed increase in the wavelength of light from most distant galaxies. This effect is called the ‘red-shift’. Be able to explain the term ‘red- shift’. c How the observed ‘red-shift’ provides evidence that the universe is expanding and supports the ‘Big Bang’ theory. Know that the further away the galaxies are, the faster they are moving, and the bigger the observed increase in wavelength. Be able to explain how ‘red-shift’ provides evidence that the universe is expanding. d Cosmic microwave background radiation (CMBR) is a form of electromagnetic radiation filling the universe. Know that the ‘Big Bang’ theory indicates that the universe began from a very small initial point. e The ‘Big Bang’ theory is currently the only theory that can explain the existence of CMBR. Know that CMBR comes from radiation that was present shortly after the beginning of the universe. Summary of P1.5 P1 Lesson 39 Summary of P1.5 Summary of section P1.5