Make your own free website on Tripod.com

A2 Module 4 Waves, Fields and Nuclear Energy

Introduction:  This is the first A2 module building on the key ideas and knowledge covered in AS. The properties of waves are covered, gravitational and electric fields are introduced, as are the magnetic effects of currents. Candidates will also study the practical application of nuclear fission as a source of energy. You MUST learn the 5 formula in bold

Oscillations and Waves

 

Simple harmonic motion: graphical and analytical treatments

Characteristic features of simple harmonic motion 

Exchange of potential and kinetic energy in oscillatory motion

Understanding and use of the following equations 

a = - (2pf)2x

x = Acos2pft

v = Ī2pf ÷A2 - x2

Graphical representations linking displacement, velocity, acceleration , time and energy 

Velocity as gradient of displacement/time graph 

Simple pendulum and mass-spring as examples and use of the equations 

T = 2l/g    simple pendulum

T = 2m/k   spring pendulum

Candidates should have experience of the use of datalogging techniques in analysing mechanical and oscillatory systems

Free and forced vibration

SHM multi choice answers from old exam collection

Qualitative treatment of free and forced vibration 

Resonance and the effects of damping 

Examples of these effects from more than one branch of Physics e.g. production of sound in a pipe instrument or mechanical vibrations in a moving vehicle

Progressive wave

Oscillation of the particles of the medium 

Amplitude, frequency, wavelength, speed, phase, path difference 

Recall and use of

c = fl

Longitudinal waves and transverse waves  

Examples including sound and electromagnetic waves 

Polarisation as evidence for the nature of transverse waves; applications, e.g. polaroid sunglasses

Superposition of waves, stationary waves

 

The formation of stationary waves by two waves of the same frequency travelling in opposite directions; no mathematical treatment required 

Simple graphical representations of stationary waves, nodes and antinodes on strings and in pipes.

Interference

 

The concepts of path difference and coherence 

Requirements of two source and single source double-slit systems for the production of fringes 

The appearance of the interference fringes produced by a double slit system.

l = ws / D

Diffraction

simple explanation of diffraction

 

Appearance of the diffraction pattern from a single slit 

The plane transmission diffraction grating at normal incidence 

Optical details of the spectrometer will not be required 

Derivation of: 

nl= d sin q

 Applications, e.g. to spectral analysis of light from stars

Capacitance  

Capacitance

 

Recall and use of C = Q /V

Energy stored by capacitor

 

Derivation and use of E = 1/2 QV

and interpretation of area under a graph of charge against p.d.

Graphical representation of charging and discharging of capacitors through resistors

time constant = RC 

Calculation of time constants including their determination from graphical data

Quantitative treatment of capacitor discharge

Q = Qo e -t/RC 

Candidates should have experience of the use of a voltage sensor and datalogger to plot discharge curve for a capacitor

Circular motion & Gravitational and electric fields

Uniform motion in a circle

w = v/r   w = 2pf   a = v2 / r  = rw2

where  is w angular speed

Centripetal force equation

Recall and use of

F = - mv2 / r

Gravity, Newtonís law, the gravitational constant

F = - Gm1m2 / r2

Methods for measuring G are not included

Gravitational field strength

g=F/m   g = -GM/r2 (radial field)

g = -DV/Dr

Gravitational potential V

V = -GM/r radial field) 

Graphical representations of variations of g and V with r

Motion of masses in gravitational fields

Circular motion of planets and satellites including geo-synchronous orbits

Coulombís law, permittivity of free space

Recall and use of

F = 1/4pe   Q1Q2/r2

Electric field strength E

Application, e.g. estimation of forces at closest approach in Rutherford alpha particle scattering 

E = F/Q    E= V/d (uniform field)

E = 1/4pe0  Q/r2   (radial field)

Electric potential

V = 1/4pe0  Q/r

Motion of charged particles in an electric field  

Trajectory of particle beams

Similarities and differences between electric and gravitational fields

No quantitative comparisons required

Magnetic effects of currents  

Force on a current carrying wire in a magnetic field

F = BIl (field perpendicular to current)

Motion of charged particles in a magnetic field

F = BQv (field perpendicular to velocity) 

Circular path of particles; application, e.g. charged particles in a cyclotron

Magnetic flux density B, flux f flux linkage Nf

f = BA, B normal to A

Electromagnetic induction

 

 

Simple experimental phenomena, Faradayís and Lenzís laws For a flux change at a uniform rate 

magnitude of induced e.m.f. = N Df / Dt

Applications, e.g. p.d. between wing-tips of aircraft in flight

Nuclear applications  

Mass and energy

 

Simple calculations on nuclear transformations; mass difference; binding energy

Atomic mass unit, u

Conversion of units; 1u = 9 31.1 Mev

E = mc≤

Appreciation that E = mc≤ applies to all energy changes

Graph of average binding energy per nucleon against nucleon number, A

Fission and fusion processes.

Induced fission

Induced fission by thermal neutrons

Possibility of a chain reaction

Critical mass

Need for a moderator in thermal reactors

Control of the reaction rate

Factors influencing choice of material for moderator, control rods and coolant

Examples of materials

Safety aspects

Fuel used, shielding, emergency shut-down

Production, handling and disposal of active wastes

Artificial transmutation

Production of man-made nuclides and examples of their practical applications, e.g. in medical diagnosis.

Waves and nuclear applications past questions from old A-level PH02 Summer2001 to Spring1998

Waves and nuclear applications past questions from old A-level PH02 Summer1997 to Spring1995

Waves and Nuclear Energy - Interactive Glossary

An online exam paper that covers material from this topic

 

Click this button to try out some quizzes

It's a link to a few multiple choice quizzes I wrote last year.  N.B. as yet there are NO resources in FunBrain that cover material from this module.  So far all there are only mechanics and astrophysics quizzes.

Further Links

Syvum.com: Gravitation Web Info and Multi-choice