edexcel ias physics

• 1 be able to use the equations for uniformly accelerated motion in one dimension:
  • s = (u + v)t/2
  • v = u + at,
  • s = ut + 1/2 at2
  • v2 = u2 + 2as
• 2 be able to draw and interpret displacement-time, velocity-time and acceleration- time graphs
• 3 know the physical quantities derived from the slopes and areas of displacement- time, velocity-time and acceleration-time graphs, including cases of non-uniform acceleration and understand how to use the quantities
• 4 understand scalar and vector quantities and know examples of each type of quantity and recognise vector notation
• 5 be able to resolve a vector into two components at right angles to each other by drawing and by calculation
• 6 be able to find the resultant of two coplanar vectors at any angle to each other by drawing, and at right angles to each other by calculation
• 7 understand how to make use of the independence of vertical and horizontal motion of a projectile moving freely under gravity
• 8 be able to draw and interpret free-body force diagrams to represent forces on a particle or on an extended but rigid body using the concept of centre of gravity of an extended body
• 9 be able to use the equation ∑F = ma, and understand how to use this equation in situations where m is constant (Newton’s second law of motion), including Newton’s first law of motion where a = 0, objects at rest or travelling at constant velocity Use of the term ‘terminal velocity’ is expected.
• 10 be able to use the equations for gravitational field strength g = mF and weight W = mg

• 11 CORE PRACTICAL 1: Determine the acceleration of a freely-falling object

• 12 know and understand Newton’s third law of motion and know the properties of pairs of forces in an interaction between two bodies
• 13 understand that momentum is defined as p = mv
• 14 know the principle of conservation of linear momentum, understand how to relate this to Newton’s laws of motion and understand how to apply this to problems in one dimension
• 15 be able to use the equation for the moment of a force, moment of force = Fx where x is the perpendicular distance between the line of action of the force and the axis of rotation
• 16 be able to use the concept of centre of gravity of an extended body and apply the principle of moments to an extended body in equilibrium
• 17 be able to use the equation for work ∆W = F∆s, including calculations when the force is not along the line of motion
• 18 be able to use the equation Ek = 12 mv2 for the kinetic energy of a body energy near the Earth’s surface
• 19 be able to use the equation ∆Egrav = mg∆h for the difference in gravitational potential
• 20 know, and understand how to apply, the principle of conservation of energy including use of work done, gravitational potential energy and kinetic energy
• 21 be able to use the equations relating power, time and energy transferred or work done P = Et and P = W/t
• 22 be able to use the equations efficiency = useful energy output / total energy input and efficiency = useful power output / total power input

• 23 be able to use the equation density ρ = V/m
• 24 understand how to use the relationship upthrust = weight of fluid displaced
• 25
  • a be able to use the equation for viscous drag (Stokes’Law), F = 6πηrv.
  • b understand that this equation applies only to small spherical objects moving at low speeds with laminar flow (or in the absence of turbulent flow) and that viscosity is temperature dependent

• 26 CORE PRACTICAL 2: Use a falling-ball method to determine the viscosity of a liquid

• 27 be able to use the Hooke’s law equation, ∆F = k∆x, where k is the stiffness of the object
• 28 understand how to use the relationships
  • (tensile or compressive) stress = force/cross-sectional area
  • (tensile or compressive) strain= change in length/original length Young modulus = stress/strain.
• 29
  • a be able to draw and interpret force-extension and force-compression graphs
  • b understand the terms limit of proportionality, elastic limit, yield-point, elastic deformation and plastic deformation and be able to apply them to these graphs
• 30 be able to draw and interpret tensile or compressive stress-strain graphs, and understand the term breaking stress

• 31 CORE PRACTICAL 3: Determine the Young modulus of a material

• 32 be able to calculate the elastic strain energy Eel in a deformed material sample, using the equation ∆Eel = 1/2 F∆x , and from the area under the force-extension graph The estimation of area and hence energy change for both linear and non-linear force-extension graphs is expected.

• 33 understand the terms amplitude, frequency, period, speed and wavelength
• 34 be able to use the wave equation v = fλ
• 35 be able to describe longitudinal waves in terms of pressure variation and the displacement of molecules
• 36 be able to describe transverse waves
• 37 be able to draw and interpret graphs representing transverse and longitudinal waves including standing/stationary waves

• 38 CORE PRACTICAL 4: Determine the speed of sound in air using a 2-beam oscilloscope, signal generator, speaker and microphone

• 39 know and understand what is meant by wavefront, coherence, path difference, superposition, interference and phase
• 40 be able to use the relationship between phase difference and path difference
• 41 know what is meant by a standing/stationary wave and understand how such a wave is formed, know how to identify nodes and antinodes

• 43 CORE PRACTICAL 5: Investigate the effects of length, tension and mass per unit length on the frequency of a vibrating string or wire

• 42 be able to use the equation for the speed of a transverse wave on a string v = T/μ
• 44 be able to use the equation for the intensity of radiation I = P/A
• 45 know and understand that at the interface between medium 1 and medium 2 n1 sin(θ1)= n2 sin(θ2) where refractive index is n = c/v
• 46 be able to calculate critical angle using sinC = 1 n
• 47 be able to predict whether total internal reflection will occur at an interface
• 48 understand how to measure the refractive index of a solid material
• 49 understand what is meant by plane polarisation
• 50 understand what is meant by diffraction and use Huygens’ construction to explain what happens to a wave when it meets a slit or an obstacle
• 51 be able to use nλ = dsinθ for a diffraction grating

• 52 CORE PRACTICAL 6: Determine the wavelength of light from a laser or other light source using a diffraction grating

• 53 understand how diffraction experiments provide evidence for the wave nature of electrons
• 54 be able to use the de Broglie equation λ = hp
• 55 understand that waves can be transmitted and reflected at an interface between media
• 56 understand how a pulse-echo technique can provide information about the position of an object and how the amount of information obtained may be limited by the wavelength of the radiation or by the duration of pulses
• 57 understand how the behaviour of electromagnetic radiation can be described in terms of a wave model and a photon model, and how these models developed over time
• 58 be able to use the equation E = hf, that relates the photon energy to the wave frequency
• 59 understand that the absorption of a photon can result in the emission of a photoelectron
• 60 understand the terms ‘threshold frequency’ and ‘work function’ and be able to use the equation h f = φ + 1/2 m (v max)2 electromagnetic radiation
• 61 be able to use the electronvolt (eV) to express small energies
• 62 understand how the photoelectric effect provides evidence for the particle nature of
• 63 understand atomic line spectra in terms of transitions between discrete energy levels and understand how to calculate the frequency of radiation that could be emitted or absorbed in a transition between energy levels.

• 64 understand that electric current is the rate of flow of charged particles and be able to use the equation I = ∆Q / ∆t
• 65 understand how to use the equation V = WQ
• 66 understand that resistance is defined by R = VI and that Ohm’s law is a special case when I ∝ V for constant temperature
• 67
  • (a) understand how the distribution of current in a circuit is a consequence of charge conservation
  • (b) understand how the distribution of potential differences in a circuit is a consequence of energy conservation 68 be able to derive the equations for combining resistances in series and parallel using the principles of charge and energy conservation, and be able to use these equations
• 68 be able to derive the equations for combining resistances in series and parallel using the principles of charge and energy conservation, and be able to use these equations
• 69 be able to use the equations P = VI, W = VIt and be able to derive and use related V2 R equations, e.g. P = I2R and P = V2/R
• 70 understand how to sketch, recognise and interpret current-potential difference graphs for components, including ohmic conductors, filament bulbs, thermistors and diodes
• 71 be able to use the equation R = ρl/A

• 72 CORE PRACTICAL 7: Determine the electrical resistivity of a material

• 73 be able to use I = nqvA to explain the large range of resistivities of different materials
• 74 understand how the potential along a uniform current-carrying wire varies with the distance along it
• 75 understand the principles of a potential divider circuit and understand how to calculate potential differences and resistances in such a circuit
• 76 be able to analyse potential divider circuits where one resistance is variable including thermistors and light dependent resistors (LDRs)
• 77 know the definition of electromotive force (e.m.f.) and understand what is meant by internal resistance and know how to distinguish between e.m.f. and terminal potential difference

• 78 CORE PRACTICAL 8: Determine the e.m.f. and internal resistance of an electrical cell

• 79 understand how changes of resistance with temperature may be modelled in terms of lattice vibrations and number of conduction electrons and understand how to apply this model to metallic conductors and negative temperature coefficient thermistors
• 80 understand how changes of resistance with illumination may be modelled in terms of the number of conduction electrons and understand how to apply this model to LDRs.

identify the apparatus required

• the range and resolution of measuring instruments including Vernier calipers (0.1mm) and micrometer screw gauge (0.01mm)
• discuss calibration of instruments, e.g. whether a meter reads zero before measurements are made
• describe how to measure relevant variables using the most appropriate instrument and correct measuring techniques
• identify and state how to control all other relevant variables to make it a fair test
• discuss whether repeat readings are appropriate
• identify health and safety issues and discuss how these may be dealt with
• discuss how the data collected will be used
• identify possible sources of uncertainty and/or systematic error and explain how these may be reduced or eliminated
• comment on the implications of physics (e.g. benefits/risks) and on its context (e.g. social/environmental/historical).

• comment on the number of readings taken
• comment on the range of measurements taken * comment on significant figures
• check a reading that is inconsistent with other readings, e.g. a point that is not on the line of a graph – students may be shown a diagram of a micrometer that is being used to measure the diameter of a wire and be expected to write down the reading to the correct number of significant figures
• comment on how the experiment may be improved, possibly by using additional apparatus (e.g. to reduce errors) – examples may include using a set square to determine whether a ruler is vertical to aid the measurement of the extension of a spring.

• perform calculations, using the correct number of significant figures
• plot results on a graph using an appropriate scale
• use the correct units throughout
• comment on the relationship obtained from the graph
• determine the relationship between two variables or determine a constant with the aid of a graph, e.g. by determining the gradient using a large triangle
• suggest realistic modifications to reduce errors
• suggest realistic modifications to improve the experiment * discuss uncertainties, qualitatively and quantitatively
• determine the percentage uncertainty in measurements for a single reading using half the resolution of the instrument and from multiple readings using the half range (students are not expected to compound percentage uncertainties).

• 81 understand how to use the equation impulse = F∆t =∆p (Newton’s second law of motion)

• 82 CORE PRACTICAL 9: Investigate the relationship between the force exerted on an object and its change of momentum

• 83 understand how to apply conservation of linear momentum to problems in two dimensions

• 84 CORE PRACTICAL 10: Use ICT to analyse collisions between small spheres, e.g. ball bearings on a table top

• 85 understand how to determine whether a collision is elastic or inelastic
• 86 be able to derive and use the equation Ek = p2 / 2m for the kinetic energy of a non- relativistic particle
• 87 be able to express angular displacement in radians and in degrees, and convert between these units
• 88 understand what is meant by angular velocity and be able to use the equations v = ωr and T = 2π / ω
• 89 be able to use vector diagrams to derive the equations for centripetal acceleration a = v2 / r = rω2 and understand how to use these equations
• 90 understand that a resultant force (centripetal force) is required to produce and maintain circular motion
• 91 be able to use the equations for centripetal force F = ma = mv2 / r = mrω2

• 92 understand that an electric field (force field) is defined as a region where a charged particle experiences a force
• 93 understand that electric field strength is defined as E = F/Q and be able to use this equation
• 94 be able to use the equation F = Q1 Q2 / 4πε0r2 for the force between two charges 4πε0r
• 95 be able to use the equation E = Q / 4πε0r2 for the electric field due to a point charge
• 96 know and understand the relation between electric field and electric potential
• 97 be able to use the equation E = V/d for an electric field between parallel plates
• 98 be able to use V = Q / 4πε0r for a radial field
• 99 be able to draw and interpret diagrams using field lines and equipotentials to describe radial and uniform electric fields
• 100 understand that capacitance is defined as C = Q / V and be able to use this equation
• 101 be able to use the equation W = 1/2 QV for the energy stored by a capacitor, be able to derive the equation from the area under a graph of potential difference against charge stored and be able to derive and use the equations W = 1/2 CV2 and W = 1/2 (Q2)/C
• 102 be able to draw and interpret charge and discharge curves for resistor capacitor circuits and understand the significance of the time constant RC

• 103 CORE PRACTICAL 11: Use an oscilloscope or data logger to display and analyse the potential difference (p.d.) across a capacitor as it charges and discharges through a resistor

• 104 be able to use the equation Q = Q0e-t/RC and derive and use related equations for exponential discharge in a resistor-capacitor circuit, I = I0 e -t/RC, and V = V0 e -t/RC and the corresponding log equations lnQ = lnQ0 − t/RC , ln I = ln I0 − t/RC and lnV = lnV0 − t/RC
• 105 understand and use the terms magnetic flux density B, flux φ and flux linkage Nφ
• 106 be able to use the equation F = Bqv and apply Fleming’s left-hand rule to current charged particles moving in a magnetic field
• 107 be able to use the equation F = BIl sinθ and apply Fleming’s left-hand rule to carrying conductors in a magnetic field
• 108 understand the factors affecting the e.m.f. induced in a coil when there is relative motion between the coil and a permanent magnet
• 109 understand the factors affecting the e.m.f. induced in a coil when there is a change of current in another coil linked with this coil
• 110 understand how to use Faraday’s law to determine the magnitude of an induced e.m.f. and be able to use the equation that combines Faraday’s and Lenz’s laws E = −d(Nφ)/dt

• 111 understand what is meant by nucleon number (mass number) and proton number (atomic number)
• 112 understand how large-angle alpha particle scattering gives evidence for a nuclear model of the atom and how our understanding of atomic structure has changed over time
• 113 understand that electrons are released in the process of thermionic emission and how they can be accelerated by electric and magnetic fields
• 114 understand the role of electric and magnetic fields in particle accelerators (linac and cyclotron) and detectors (general principles of ionisation and deflection only)
• 115 be able to derive and use the equation r = p/BQ for a charged particle in a magnetic field
• 116 be able to apply conservation of charge, energy and momentum to interactions between particles and interpret particle tracks
• 117 understand why high energies are required to investigate the structure of nucleons
• 118 be able to use the equation ∆E = c2∆m in situations involving the creation and annihilation of matter and antimatter particles
• 119 be able to use MeV and GeV (energy) and MeV/c2, GeV/c2 (mass) and convert between these and SI units
• 120 understand situations in which the relativistic increase in particle lifetime is significant (use of relativistic equations not required) 121 know that in the standard quark-lepton model particles can be classified as:
  • baryons (e.g. neutrons and protons), which are made from three quarks
  • mesons (e.g. pions), which are made from a quark and an antiquark
  • leptons (e.g. electrons and neutrinos), which are fundamental particles
  • photons and that the symmetry of the model predicted the top quark
• 122 know that every particle has a corresponding antiparticle and be able to use the properties of a particle to deduce the properties of its antiparticle and vice versa
• 123 understand how to use laws of conservation of charge, baryon number and lepton number to determine whether a particle interaction is possible
• 124 be able to write and interpret particle equations given the relevant particle symbols.

• 125 be able to use the equations ΔE = mcΔθ and ΔE = LΔm

• 126 CORE PRACTICAL 12: Calibrate a thermistor in a potential divider circuit as a thermostat

• 127 CORE PRACTICAL 13: Determine the specific latent heat of a phase change

• 128 understand the concept of internal energy as the random distribution of potential and kinetic energy amongst molecules
• 129 understand the concept of absolute zero and how the average kinetic energy of molecules is related to the absolute temperature
• 130 be able to use the equation pV = NkT for an ideal gas

• 131 CORE PRACTICAL 14: Investigate the relationship between pressure and volume of a gas at fixed temperature

• 132 be able to derive and use the equation 1/2 m = 3/2 kT

• 133 understand the concept of nuclear binding energy and be able to use the equation ΔE = c2Δm in calculations of nuclear mass (including mass deficit) and energy
• 134 use the atomic mass unit (u) to express small masses and convert between this and SI units
• 135 understand the processes of nuclear fusion and fission with reference to the binding energy per nucleon curve
• 136 understand the mechanism of nuclear fusion and the need for very high densities of matter and very high temperatures to bring about and maintain nuclear fusion
• 137 understand that there is background radiation and how to take appropriate account of it in calculations
• 138 understand the relationships between the nature, penetration, ionising ability and range in different materials of nuclear radiations (alpha, beta and gamma)
• 139 be able to write and interpret nuclear equations given the relevant particle symbols

• 140 CORE PRACTICAL 15: Investigate the absorption of gamma radiation by lead

• 141 understand the spontaneous and random nature of nuclear decay
• 142 be able to determine the half-lives of radioactive isotopes graphically and be able to use the equations for radioactive decay activity A = λN, dN/dt = -λN, λ = ln2/t(1/2), N = N0 e-λt and A = A0 e-λt and derive and use the corresponding log equations.

• 143 understand that the condition for simple harmonic motion is F = − kx, and hence understand how to identify situations in which simple harmonic motion will occur
• 144 be able to use the equations a = − ω2x, x = Acos ωt, v = − Aω sin ωt, a=−Aω2cosωt,and T = 1/f = 2π/ω and ω = 2πf as applied to a simple fω harmonic oscillator
• 145 be able to use equations for a simple harmonic oscillator T = 2π sqrt(m/k), and a simple pendulum T = 2π sqrt(l/g)
• 146 be able to draw and interpret a displacement-time graph for an object oscillating and know that the gradient at a point gives the velocity at that point
• 147 be able to draw and interpret a velocity-time graph for an oscillating object and know that the gradient at a point gives the acceleration at that point
• 148 understand what is meant by resonance

• 149 CORE PRACTICAL 16: Determine the value of an unknown mass using the resonant frequencies of the oscillation of known masses

• 150 understand how to apply conservation of energy to damped and undamped oscillating systems
• 151 understand the distinction between free and forced oscillations
• 152 understand how the amplitude of a forced oscillation changes at and around the natural frequency of a system and know, qualitatively, how damping affects resonance
• 153 understand how damping and the plastic deformation of ductile materials reduce the amplitude of oscillation.

• 154 understand that a gravitational field (force field) is defined as a region where a mass experiences a force
• 155 understand that gravitational field strength is defined as g = mF and be able to use this equation
• 156 be able to use the equation F = Gm1m2 (Newton’s law of universal gravitation) r2 −Gm
• 157 be able to derive and use the equation g = Gm/r2 for the gravitational field due to a point mass
• 158 be able to use the equation Vgrav = -Gm/r for a radial gravitational field
• 159 be able to compare electric fields with gravitational fields
• 160 be able to apply Newton’s laws of motion and universal gravitation to orbital motion
• 161 understand what is meant by a black body radiator and be able to interpret radiation curves for such a radiator
• 162 be able to use the Stefan-Boltzmann law equation L = σAT4 for black body radiators
• 163 be able to use Wien’s law equation λmaxT = 2.898 x 10-3 mK for black body radiators
• 164 be able to use the equation, intensity I = L/4πd2 where L is luminosity and d is distance from the source
• 165 understand how astronomical distances can be determined using trigonometric parallax
• 166 understand how astronomical distances can be determined using measurements of intensity received from standard candles (objects of known luminosity)
• 167 be able to sketch and interpret a simple Hertzsprung-Russell diagram that relates stellar luminosity to surface temperature
• 168 understand how to relate the Hertzsprung-Russell diagram to the life cycle of stars
• 169 understand how the movement of a source of waves relative to an observer/detector gives rise to a shift in frequency (Doppler effect)
• 170 be able to use the equations for redshift z = ∆λ/λ ≈ ∆f/f ≈ v / c for a source of electromagnetic radiation moving relative to an observer and v = H0d for objects at cosmological distances
• 171 understand the controversy over the age and ultimate fate of the universe associated with the value of the Hubble constant and the possible existence of dark matter.

• identify the most appropriate apparatus, giving details. These may include the range and resolution of instruments and/or relevant dimensions of apparatus (e.g. the length of string used for a pendulum)
• discuss calibration of instruments, e.g. whether a meter reads zero before measurements are made
• describe how to measure relevant variables using the most appropriate instrument(s) and techniques
• identify and state how to control all other relevant variables to make it a fair test
• discuss whether repeat readings are appropriate
• identify health and safety issues and discuss how these may be dealt with
• discuss how the data collected will be used.

• comment on how the experiment could have been improved, possibly by using additional apparatus (e.g. to reduce errors) – examples may include using set squares to measure the diameter of a cylinder and using a marker for timing oscillations
• comment on the number of readings taken
• comment on the range of measurements taken
• comment on significant figures – students may be required to identify and/or round up any incorrect figures in a table of results
• identify and/or amend units that are incorrect
• identify and check a reading that is inconsistent with other readings, e.g. a point that is not on the line of a graph.

• perform calculations, using the correct number of significant figures
• plot results on a graph using an appropriate scale and units – the graph could be logarithmic in nature
• use the correct units throughout
• comment on the trend/pattern obtained
• determine the relationship between two variables or determine a constant with the aid of the graph, e.g. by determining the gradient using a large triangle
• use the terms precision, accuracy and sensitivity appropriately suggest realistic modifications to reduce errors
• suggest realistic modifications to improve the experiment
• discuss uncertainties qualitatively and quantitatively
• compound percentage uncertainties correctly
• determine the percentage uncertainty in measurements for a single reading using half the resolution of the instrument and from multiple readings using the half range.