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Y11 Doubles Physics Keyword List
P2 7 Energy from the Nucleus
Word
nuclear fission
chain reaction
fission neutrons
nuclear fission
reactor
fissionable isotope
moderator
control rod
coolant
fuel rod
pressuriser
heat exchanger
nuclear fusion
plasma
fusion reactor
deuterium
tritium
background
radiation
radiation dose
Chernobyl
Definition
The process in which one large nucleus (e.g. uranium-235 or
plutonium-239) splits into two smaller nuclei, releasing a large
amount of energy and two or more neutrons.
Reactions in which one reaction causes further reactions, which in
turn causes further reactions, etc. A nuclear chain reaction occurs
when fission neutrons cause further fission, so more fission neutrons
are released, which can go on to cause further fission.
Slow neutrons which can be absorbed by an unstable large nucleus.
The area in a nuclear power station which holds the nuclear fuel rods.
An isotope which can undergo fission.
A substance used to slow down fission neutrons so that they can
cause further fission. Water is often used as a moderator in nuclear
power stations.
Rods which are used to absorb excess neutrons in a nuclear fission
reactor to control the rate of energy released.
A fluid used to gain kinetic energy from the neutrons and fuel rods in
a nuclear reactor. Water is often used as a coolant in nuclear power
stations.
Rods containing the fuel in a nuclear power station.
A device used to increase the pressure of a fluid. Pressurisers can be
used to keep fluids as liquids, even if their temperature rises above
the boiling point at normal atmospheric pressure.
A system which allows the heat from one substance to be transferred
to another substance. Heat exchangers are used in nuclear power
stations to prevent external water sources from becoming
contaminated.
The process in which two small nuclei are fused together to form one
larger nucleus. A large amount of energy is released in this process.
A superheated gas where all atoms are fully ionised, such that the
nuclei are bare, with no electrons.
A machine designed to cause nuclear fusion to occur.
A hydrogen isotope with one proton and one neutron.
A hydrogen isotope with one proton and two neutrons.
The level of radiation which naturally occurs in an environment.
The level of radiation that a person is exposed to.
A district in Ukraine. It is the site of a nuclear power station which
exploded in 1986 and has since been evacuated.
The Big Bang
galaxy
Milky Way
gravity
protostar
main sequence star
red giant
white dwarf
black dwarf
red supergiant
supernova
neutron star
black hole
planet
light elements
heavy elements
Solar System
The theory that the universe was created in a massive explosion (the
Big Bang) and that the universe has been expanding ever since.
A collection of billions of stars.
The galaxy in which we are located.
The force of attraction between any two objects.
The concentration of dust cloud and gas in space that forms a star.
The main stage in the life of a star during which it radiates energy
because of fusion of hydrogen nuclei in its core.
A star that has expanded and cooled, resulting in it becoming red and
much larger and cooler than it was before it expanded.
A star that has collapsed from the red giant stage to become much
hotter and denser than it was before.
A star that has faded out and become cold.
An extremely large red giant star.
The explosion of a massive star after fusion in its core stops and the
matter surrounding its core collapses onto the core and rebounds.
The highly compressed core of a massive star that remains after a
supernova explosion.
An object in space that has so much mass that nothing, not even
light, can escape from its gravitational field.
A large object that moves in an orbit around a star. A planet reflects
light from the star and does not produce its own light.
Elements that are no heavier than iron, and have a mass number no
greater than 56.
Elements heavier than iron and with a mass number greater than 56.
The Sun and the objects which orbit it. This includes planets, dwarf
planets, their moons, comets and asteroids.
P2 1 Motion
Word
Definition
distance-time graph A graph with distance plotted on the y-axis and time plotted on the xaxis.
gradient
The steepness of a line on a graph.
speed
How fast an object is travelling.
average speed
On average, how fast an object is travelling. It is the total distance
divided by the total time.
velocity
The speed of an object in a given direction.
velocity-time graph A graph with velocity plotted on the y-axis and time plotted on the xaxis.
acceleration
The rate of change in velocity of an object. Acceleration can be due to
a change in speed, or a change in direction.
deceleration
The rate at which an object is slowing down.
(negative
acceleration)
P2 2 Forces
Word
force
newton (N)
motive force
Definition
gravity
air resistance
A push or a pull.
The unit of force.
Sometimes called the ‘engine force’ or ‘thrust’, it is the force
provided by a machine to make things move.
A resistive force that occurs when two surfaces move over one
another.
A single force that has the same effect as all of the forces acting on an
object.
The force of attraction between any two objects.
A force that acts to slow things down as they move through air.
water resistance
A force that acts to slow things down as they move through water.
velocity
acceleration
The speed of an object in a given direction.
The rate of change in velocity of an object. Acceleration can be due to
a change in speed, or a change in direction.
The quantity of matter in an object.
The force needed to stop a vehicle.
The distance shortest distance a vehicle can stop in. It consists of
both the thinking distance and the braking distance.
The distance travelled by a vehicle in the time it takes for the driver
to react to a situation and apply the brake.
The distance travelled by a vehicle during the time the braking force
friction
resultant force
mass
braking force
stopping distance
thinking distance
braking distance
weight
newton
gravitational field
strength
fluid
drag
terminal velocity
elastic
extension
directly
proportional
elastic potential
energy
work done
limit of
proportionality
Hooke’s law
spring constant
speed camera
anti-skid surface
acts to stop the vehicle.
The force of gravity upon an object.
The unit of weight.
The force of gravity upon an object per unit mass (the force of gravity
upon a 1 kg mass).
A liquid or gas.
The resistive force that acts upon an object moving through a fluid.
The constant velocity an object reaches when freely falling through a
fluid. The terminal velocity occurs when the size of the objects weight
is exactly balanced by the size of the drag forces upon it.
The property of an object which regains its original shape having
been deformed (e.g. squashed or stretched) by a force.
The increase in length of an object when it is stretched.
There is a directly proportional relationship between two variables
when the second variable increases at a constant rate as the first
increases. On a graph, this would be shown by a straight line through
the origin.
The energy stored in an object which has been stretched or
compressed.
The energy transferred by a force.
The limit to which a material can be stretched and still regain its
original shape. Beyond the limit of proportionality the material will be
permanently deformed.
The extension of a spring is directly proportional to the force applied,
provided its limit of proportionality is not exceeded.
The force per unit extension needed to extend a material.
A device used to monitor the speed of vehicles and record the
number plate of any vehicle exceeding the road speed limit.
A rough surface used to increase the friction between tyres and the
road to prevent vehicles skidding in poor weather conditions or at
steep gradients.
P2 3 Work, energy and momentum
Word
work done
gravitational
potential energy
kinetic energy
power
elastic potential
energy
momentum
law of conservation
of momentum
explosion
recoil
impact force
impact time
crumple zone
Definition
The energy transferred by a force.
The energy stored in an object because of its position in a
gravitational field. On Earth, the gravitational potential energy of an
object increases as the object is raised higher above the ground.
The energy of a moving object because of its motion.
The rate of energy transfer.
The energy stored in an object which has been stretched or
compressed.
The mass of an object multiplied by its velocity. It is the tendency of
an object to keep moving in the same direction. An object with more
momentum requires a larger force to stop it in a given amount of
time.
In a closed system, the total momentum before an event is equal to
the total momentum after the event.
An event which is caused by the sudden transfer of stored energy
(such as chemical or elastic potential energy) into kinetic energy.
The movement of a gun backwards when a projectile is fired from it.
Recoil occurs because momentum is conserved in the explosion.
The force between two objects in a collision.
The time over which the impact force is applied.
A region at the front and rear end of a vehicle designed to lessen the
force of an impact.