Physics A Level AQA

change in v per unit t

Acceleration of an object only acted on by force of gravity

Measurement obtained using calibrated instruments correctly

How close to the true value

Particle consisting of 2 P's and 2 N's

Max displacement of oscillating particle from equilibrium position

Particle and antiparticle meet, destroy eachother and emit radiation

Hadron w/ 3 quarks

Antiparticles with same quantum values but opposite charge to corresponding particles

Fixed point on stationary wave where amplitude is maximum

Number of P's in atom nucleus

Hadron w/ 3 quarks

Units that define the SI system:

Kg Amp S M

when B- or B+ particles are emitted following decay of a neutron-rich or proton-rich nucleus

Distance travelled by vehicle in time taken to stop

Tensile stress needed to break a solid material

Snaps without bending or stretching when subject to stress

Point through which a single force on the body has no turning affect

Charged particles that move through substance when PD applied across it

Current passing through 2 or more components in series is the same through each component

At a junction the total current in = total current out

2 or more components in series - total PD across all the components is = to sum of the PD's across each component

Sum of emf's around complete loop = sum of PD's around the loop

Constant phase difference and same frequency

Rule that: Baryon no Lepton no Charge Energy Momentum

always conserved in interactions

Strong interactions

Strong interactions

Weak interactions

Pair of equal and opposite forces acting upon the same body but not along the same line

The angle of incidence of a light ray must exceed this angle for total internal reflection to occur

Temperature at or below which a superconducting material has zero resistivity

Interval for an oscillating particle from a certain displacement and velocity to the next time the particle has identical displacement and velocity

Matter particles have a wave-like nature

Wavelength of a matter particle

process by which atom loses energy by photon emission as electron moves to lower energy level - inner shell

mass per unit volume for substance

spreading out of waves that pass through gap or near edge

plate with close parallel slits on it

splitting of beam of white light into colours by prism

distance in a given direction from equilibrium position

force of fluid resistance on an object moving through fluid

stretches easily without breaking

ratio of useful energy transferred to energy supplied to it

output power/input power

point beyond which wire is permanently stretched

property of solid that allows it to regain shape after being deformed

process of electrical conduction in a solution or molten substance due to charged ions moving to oppositely charged electrode

solution that conducts electricity

force or interaction between 2 charged objects

wavepacket or photon consisting of transverse electic and magnetic waves in phase and at right angle to eachother

electrical energy per unit charge produced inside electrical source

work done when an electron is moved through a PD of 1V

optical fibre device used to see inside cavities

capacity to do work

discrete energy levels that electrons take in shells of atom

object in rest or constant motion

uncertainty representation on a graph

uncertainty of a measurement

process in which atom absorbs energy without becoming ionised when electron moves from inner shell to higher energy level in outer shell

pattern of stationary waves on a string when it oscillates at lowest possible frequency

emission of visible photons after atoms deexcite

number of cycles of a wave that pass a point per second

force opposing the motion of a surface that moves or tries to move across another surface

high energy photons emitted by unstable nuclei or produced in particle annihilations

force per unit mass on small object in gravitational field

lowest energy state of an atom

particles and anti that can interact through the strong interaction

the extension of a spring is proportional to the force applied to it

resistance of an object to a change of its motion

formation of points of cancellation and reinforcement where two coherent waves pass through eachother

resistance inside the source of electrical energy - loss of PD per unit current in the source when current passes through it

charged atom

process of creating ions

atoms of the same element with a different number of neutrons and the same number of protons

meson that has a strange quark and another quark

energy of an object due to its motion

produces coherent, parallel beam of monochromatic light

particles that cannot interact through the strong interation

resistance decreases in light

limit beyond which - if a wire or spring is stretched - the extension is no longer proportional to the force applied

waves with particles that oscillate parallel to the direction of propagation of the wave

measure of inertia of the motion of an object

wave-like behaviour of particles

hadron w/ quark and antiquark pair

lengthening of a light pulse as it travels along optical fibre due to continual total internal reflection of waves meaning some rays travel longer distance than others in fibre

about a point is the force x perpendicular distance from the line of action of the force to the point

negatively charged lepton with a greater rest mass than the electron

resistance of a semiconductor decreases when its temperature is increased

uncharged lepton with a lower rest mass than the electron

object remains at rest or in uniform motion unless acted upon by a resultant force

rate of change of momentum of an object is proportional to the resultant force applied to it

fixed point on a stationary wave where displacement is zero

N or P in nucleus

number of P's or N's in the nucleus

type of nucleus with a particular number of P's and N's

PD across a metallic conductor is proportional to the current - if physical conditions remain constant

thin, flexible transparent fibre used to carry light pulses from one end to another

gamma photon changed in a particle and corresponding antiparticle

difference in the distances from two coherent sources to an interference fringe

time for one complete cycle of a wave to pass a point

the fraction of a cycle between the oscillations of 2 oscillating particles - measured in radians

emission of electrons from metal surface when surface is hit with light with photons of frequency greater than threshold frequency

packet or 'quantum' of electromagnetic waves