key words Flashcards
acceleration
change of velocity per unit time
acceleration of free fall
acceleration of an object acted on only by the force of gravity
accurate
a measurement that is obtained, using calibrated instruments correctly
accuracy
how close a measurement or answer is to the true value
alpha radiation
particles that each consist of two protons and two neutrons
amplitude
maximum displacement of a vibrating particle.
annihilation
when a particle and its antiparticle meet, they destroy each other and become radiation
antibaryon
a hardon consisting of three antiquarks
antimatter
antiparticles that each has the same rest mass and, if charged, have an equal and opposite charge to the corresponding particle
antimuon
the antiparticle of the muon
antineutrino
the antiparticle of the neutrino
antinode
fixed point in a stationary wave pattern where the amplitude is a maximum
antiparticle
there is an antiparticle for every type of particle
antiquark
antiparticle of a quark
atomic number
the number of protons in the nucleus of an atom
baryon
a hardon consisting of three quarks
base units
the units that define the SI system
beta radiation
B- particles are fast-moving electrons emitted by unstable neutron-rich nuclei or by free neutrons when they decay
braking distance
the distance travelled by a vehicle in the time taken to stop it
breaking stress
ultimate tensile stress
brittle
snaps without stretching or bending when subject to stress
centre of mass
the centre of mass of a body has no turning effect
charge carriers
charged particles that move through a substance when a pd is applied across it
circuit rule current
- current passing through two or more components in series
2. at a junction its split