Rhyl High School Physics Department

1 VIBRATIONS
CONTENT

• 1.1 Physical and mathematical treatment of undamped simple harmonic motion.
• 1.2 Energy interchanges during simple harmonic motion.
• 1.3 Damping of oscillations.
• 1.4 Free oscillations, forced oscillations and resonance.

1. define simple harmonic motion as a statement in words,
2. recall, recognise and use a = – ω²y as a mathematical defining equation of simple harmonic motion,
3. recall and use y = Asin (ωt + ε) as a solution to a = – ω²y,
4. explain the terms frequency, period, amplitude, angular frequency and phase constant,
5. express the period in terms of frequency and angular frequency,
6. recall and use v = A ω cos ωt and v = +/- ω (A² - y²)½ as equations for the velocity during simple harmonic motion,
7. illustrate and interpret graphically the changes in displacement, velocity and acceleration with time during simple harmonic motion,
8. illustrate and interpret graphically the changes in velocity and acceleration with displacement during simple harmonic motion,
9. recall, derive and use expressions for the periods of a simple pendulum and a mass-spring system,
10. illustrate and interpret graphically the interchange between kinetic energy and potential energy during undamped simple harmonic motion, and show that the total energy remains constant,
11. explain qualitative ideas of damping of oscillations,
12. describe practical examples of damped oscillations, and the importance of critical damping in appropriate cases such as vehicle suspensions and moving-coil meters,
13. explain qualitative ideas of free oscillations, forced oscillations and resonance, and describe practical examples,
14. describe graphically how the amplitude of a forced oscillation changes with driving frequency, and identify the factors which determine the frequency response and sharpness of resonance,
15. appreciate that there are circumstances when resonance is useful e.g. circuit tuning, microwave cooking and other circumstances in which it should be avoided e.g. bridge design.

2. WAVES
CONTENT

• 2.1 Progressive waves.
• 2.2 Transverse and longitudinal waves.
• 2.3 Frequency, wavelength and velocity of waves

1. describe what is meant by wave motion, illustrated by vibrations in ropes, springs and ripple tanks,
2. distinguish between particle motion and wave motion,
3. explain the terms displacement, amplitude, wavelength, frequency, period and velocity of a wave,
4. illustrate and interpret graphs of displacement against time, and displacement against position,
5. recall, derive and use the equation c = ƒλ
6. recall, interpret and use the wave equation y = A sin (ωt + kx),
7. explain phase difference and phase angle,
8. distinguish between transverse and longitudinal waves,
9. represent both transverse and longitudinal waves graphically in a sinusoidal waveform.

• 3.1 Interference
• 3.2 Two-source interference patterns.
• 3.3 Stationary waves.
• 3.4 Beats.
• 3.5 Diffraction.

1. state, explain and use the principle of superposition,
2. explain what is meant by the term interference,
3. describe experiments which demonstrate two-source interference for water waves, for light, for microwaves and for sound,
4. state the conditions necessary for two-source interference to be observed, i.e. constant phase difference, vibrations in the same line,
5. describe experiments which demonstrate stationary waves, e.g. vibrations of a stretched string, for sound in air and microwaves in air,
6. identify displacement nodes and antinodes and also pressure nodes and antinodes,
7. state the differences between stationary and progressive waves,
8. describe experiments which demonstrate sound beats,
9. explain the formation of beats, recall and use beat frequency ƒ_b = ƒ₁ - ƒ₂ where ƒ₁ > ƒ₂,
10. describe diffraction as the interaction between a wave and an object, with subsequent interference between parts of the disturbed wavefront,
11. describe experiments which demonstrate diffraction of water waves and light waves.

• 4.1 Reflection.
• 4.2 Refraction.
• 4.3 Interference.
• 4.4 Diffraction.
• 4.5 Polarisation.

1. recall and use the laws of reflection at a plane surface,
2. recall and use the laws of refraction at a plane surface,
3. understand total internal reflection and critical angle and be aware of such applications as step index fibre optics,
4. recall, derive and use the equation λ = ay/D for double-slit interference,
5. explain the importance of Young's double-slit experiment in establishing the wave nature of light,
6. define coherence,
7. explain the importance of coherence in obtaining stable interference fringes,
8. give examples of coherent and incoherent sources,
9. recall and use the equation d sin θ = n λ for a diffraction grating,
10. describe experiments which demonstrate polarisation of light, and know that polarisation only occurs with transverse waves.

• 5.1 The electromagnetic spectrum.
• 5.2 Spectra-the main features of optical spectra.
• 5.3 Photoelectric effect.
• 5.4 Wave-particle duality.

1. recall the regions of the electromagnetic spectrum,
2. explain emission and absorption optical line spectra,
3. interpret Bohr's ideas of orbits, in particular the quantisation of angular momentum mvr = nh/2π and fixed-energy levels,
4. calculate photon frequency ƒ, use and recall the relationship hƒ = E₁ - E₂,
5. explain photoelectric emission and outline Millikan's photoelectric experiment,
6. recall and use Einstein's equation ½mv² = hƒ - Φ,
7. outline an experiment to determine the value of Φ,
8. appreciate that the photoelectric effect provides evidence for the particulate nature of electromagnetic radiation,
9. give a short account of wave-particle duality with reference to experimental evidence of particles behaving as waves, and waves behaving as particles,
10. recall and use λ = h/p (de Broglie).

• 6.1 The nuclear atom.
• 6.2 The nucleus.
• 6.3 Isotopes.
• 6.4 Binding energy
• 6.5 Fission and fusion.

1. demonstrate an understanding of Rutherford's a-particle experiment and explain it in terms of a nuclear atom,
2. describe a simple model for the nuclear atom, explaining the composition of the nucleus in terms of protons and neutrons,
3. distinguish between atomic mass number and atomic number and understand that nucleons (atomic mass number) = protons (atomic number) + neutrons,
4. recall and use the usual notation for the representation of nuclides e.g. ^A_ZX,
5. understand the term isotope,
6. appreciate the association between mass and energy and recall that E = mc²,
7. calculate the binding energy per nucleon for an atom,
8. describe the relevance of the binding energy per nucleon to nuclear fission and fusion.

• 7.1 Types of ionising radiation
• 7.2 Nature of the radiations
• 7.3 Half-life
• 7.4 Hazards and safety precautions

1. recognise and appreciate the spontaneous nature of nuclear decay,
2. account for the existence of background radiation,
3. describe the nature of α, β and γ radiation,
4. explain what is meant by half-life,
5. understand and use the exponential law of decay in graphical form,
6. show an awareness of the biological hazards of ionising radiation i.e. whether exposed to external radiation or when radioactive materials are absorbed (ingestion and/or inhalation).