Materials Science within AS and A-level Physics Elizabeth Swinbank Director, Salters Horners Advanced Physics University of York

Changes to AS/A-level physics All AS and A-level specifications (syllabuses) are changing for first teaching in September 2008 All the new physics specs have 4 content assessment units (2 AS, 2 A2) 2 coursework assessment units (1 AS, 1 A2) a requirement to address ‘how science works’ Most have little or no optional content See IOP summary for details of assessment structures

Materials Science content is predominantly in AS AS core content includes resistivity refractive index At AS, nearly all specs require mechanical properties Hooke’s law Young modulus stress-strain graphs elastic and plastic behaviour meaning of terms brittle, hard etc

A2 core content includes specific heat capacity There is essentially no other Materials Science content in any A2 physics specification See Appendix for details of individual spec requirements

Examples of content requirements Draw force-extension, force-compression, and tensile/ compressive stress-strain graphs. Identify the limit of proportionality, elastic limit and yield point (Edexcel) One method of measuring Young modulus and fracture stress (OCR B) Describe how to determine the resistivity of a metal wire experimentally (WJEC) Refractive index of a substance is given by n = c/v (AQA B)

How Science Works Nature and limitations of scientific knowledge (hypothesis and prediction, data and explanation, modelling, the scientific community) Scientific enquiry (experimental skills, data handling, mathematical skills) Communication (scientific language, presentation of data) Applications and implications (decision making, risk, ethics)

Coursework All specifications require practical coursework at AS and A2. Students undertake a practical task (or tasks) that are either set by the awarding body or devised by their teachers. Typically, the exercise takes about 1 hour to complete. The exact requirements vary between specifications.

Examples of AS practical coursework requirements Use and be familiar with standard laboratory equipment (eg electric meters… vernier callipers … newtonmeters... electronic balance …) (AQA) Take measurements and record data showing awareness of the limits of accuracy … (WJEC) Analyse and interpret data to provide evidence, recognising correlations and causal relationships (OCR A)

Visit or case study The Edexcel specification for AS requires a report of a visit or case study. The practical task should be linked to the visit/case study. Example Visit a biscuit factory: observe mechanical testing of products for quality control Practical: measure elastic modulus of ice-cream wafer

Materials activities from Salters Horners Advanced Physics (Edexcel) Context-led course Food industry: product development and quality control Spare part surgery: designer materials

Eat sweets to establish the meaning of technical terms brittle, hard, etc  

Plot force-extension graphs for strawberry laces

Measure Brinnell hardness of mints

Measure breaking stress of model bone

Determine Young modulus of UHMWPE for use in hip replacements

A blueprint for the development of Materials Science resources Focus on mechanical properties for AS level Include electrical, thermal and optical properties Address ‘how science works’ Develop experimental skills Put activities in authentic (and novel) contexts

Appendix Materials Science elements of the new AS and A-level physics specifications AQA A AQA B (Physics in Context) Edexcel (includes SHAP) OCR A OCR B (Advancing Physics) WJEC

AQA A resistivity Unit 1 Particles, Quantum Phenomena and Electricity superconductivity Unit 2 Mechanics, Materials and Waves density Hooke’s law tensile stress and strain energy stored breaking stress plastic behaviour fracture and brittleness stress-strain curves Young modulus

AQA A specific heat capacity Unit 5 Nuclear Physics, Thermal Physics and an Optional Topic specific heat capacity

AQA B (Physics in context) Unit 1 Harmony and Structure in the Universe refractive index Unit 2 Physics Keeps us Going elastic potential energy stiffness (of a sample) thermal conductivity U values resistivity superconductivity Unit 5 Energy Under the Microscope specific heat capacity

Edexcel (SHAP) density Unit 1 Physics on the go laminar and turbulent flow viscosity and Stokes’s law Hooke’s law compressive and tensile stress and strain stress-strain graphs Young modulus elastic and plastic behaviour breaking stress energy stored meaning of brittle, hard, ductile, malleable, stiff, tough

Edexcel (SHAP) resistivity Unit 2 Physics at work temperature and resistance refractive index Unit 5 Physics from creation to collapse specific heat capacity

OCR A tensile and compressive deformation Unit 1 Mechanics Hooke’s law stored energy stress and strain Young modulus breaking stress elastic and plastic deformation stress-strain graphs Unit 2 Electrons, Waves and Photons resistivity temperature and resistance superconductivity

OCR B (Advancing Physics) Unit 1 Physics in action: designer materials mechanical behaviour deformation and fracture stress, strain Young modulus stiff, elastic, plastic, ductile, hard, brittle, tough stress-strain graphs size and spacing of particles metals, ceramics, polymers, composites electrical behaviour metals, semiconductors, insulators resistivity, conductivity

OCR B (Advancing Physics) Unit 4 Rise and Fall of the Clockwork Universe specific heat capacity

WJEC (Wales) stored energy Unit 1 Motion, Energy and Charge density Hooke’s law friction viscosity resistivity superconductivity Unit 2 Waves and Particles refractive index

WJEC (Wales) Unit 4 Oscillations and Fields stiffness (of a sample) specific heat capacity